Shells and airstrikes rained down on opposition-held parts of Aleppo Thursday, despite a temporary ceasefire designed to allow humanitarian aid into the contested Syrian city, activists said.

Unidentified warplanes mounted dozens of strikes on rebel-held districts in south-western Aleppo, which has effectively been a divided city since mid-2012, the Syrian Observatory for Human Rights reported.

Clashes were also under way between rebels and regime forces in the area, said the Britain-based Observatory, which relies on a network of activists inside Syria for its information.

At least five rebels were killed, the watchdog said. It did not report casualties among regime forces.

On Wednesday, Russia, a key ally of Syrian President Bashar al-Assad, said all military hostilities in Aleppo would halt for three hours a day for three consecutive days starting Thursday to allow humanitarian convoys to deliver aid to civilians there.

The ceasefire had been due to begin at 10 am local time (0700 GMT).

Brita Hagi Hassan, the head of the Aleppo Local Council on the rebel side, dismissed Russia's truce announcement as "mere media propaganda."

"Their planes have not left the Aleppo skies," Hassan told dpa in a Facebook message.  

Meanwhile, activists inside Aleppo reported that regime helicopters dropped barrels allegedly containing chlorine gas on the city's opposition-held district of Zabadieh late Wednesday, killing a woman and her child.  

Activist Mahmoud al-Shami, based in the rebel side of Aleppo, posted pictures on his Facebook page showing a father and his 1-year-old baby being treated for breathing problems allegedly caused by chlorine inhalation.

The claims could not be independently verified.

Chlorine gas can cause breathing problems and foaming blood from the mouth.

French Foreign Minister Jean-Marc Ayrault expressed concern about the alleged chlorine attack.

"I strongly condemn all attacks on the civilian population, all the more when chemical weapons are used," Ayrault said in a statement.

The Syrian government and rebels have been repeatedly accused of using banned chemical agents in the conflict, now in its sixth year.

There has been a spike in attacks on medical facilities in Syria in recent months, Human Rights Watch said on Thursday.

"Airstrikes on hospitals are becoming routine in Syria, but we have yet to see any investigation or accountability for these criminal acts," said Nadim Houry, the watchdog's deputy Middle East director, said.

"With heavy bombing continuing relentlessly in Aleppo especially, hospitals and clinics need to be treated as the sacred life-saving places they are, not as additional bombing targets," he added.

The Islamic state extremist militia has taken advantage of Syria's strife to establish a foothold in the country.

The al-Qaeda splinter group has suffered military setbacks and lost ground in Syria since September, when Russia started an air campaign in the country in support of al-Assad.

At least 30 people, including 24 civilians, were killed Thursday in airstrikes by Russian jets targeting al-Raqqa, the Islamic State's de facto capital in Syria, the Observatory said.

The synchronized strikes also left 70 injured and an unspecified number of missing people in the north-eastern city.

"Today's air raids in al-Raqqa were the fiercest in about three months," Mohammed Ibrahim, a doctor in a local hospital, said.

He added at least 16 raids were carried out by Russian aircraft against civil sites in the city.

"There are no longer obvious positions for Daesh in al-Raqqa," Ibrahim told dpa, using an Arabic acronym for Islamic State.

In Moscow, the Russian Defence Ministry said its long-range Tupolev-22M3 bombers had hit a number of Islamic State targets, including a chemical ammunition plant near al-Raqqa.

"Six long-range Tupolev-22M3 bombers took off from a base in Russia to deal a pinpoint strike with high-explosive fragmentation bombs against facilities of the terrorist group called Islamic State in the south-east, north and north-west of Raqqa," the Defense Ministry added, according to state news agency TASS.

On Monday, Russian bombers attacked Islamic State's facilities near Palmyra in central Syria. 

Latest news

Syrian opposition rules out future role for President al-Assad

The Syrian opposition said Friday it would not accept any role for President Bashar al-Assad in the future of the war-torn country, reacting to a recent US shift saying that removing al-Assad is no longer a priority for Washington.

Russian Army integrates breakaway forces of Georgian province

Parts of the small fighting forces of the Georgian breakaway province of South Ossetia have been placed under Russian military control, Russian Defence Minister Sergei Shoigu said on Friday.

Czech Republic's Pilsner Urquell beer is now Japanese

Japanese brewing company Asahi completed its takeover of the Czech brewery Pilsner Urquell on Friday, Asahi said in a statement.

Judge approves 25-million-dollar settlement of Trump University case

A US district judge on Friday approved a 25-million-dollar settlement of lawsuits and state fraud allegations against Trump University, the US president's now-defunct business venture.

Former Thai premier Thaksin to junta on reconciliation: 'Cut me out'

Former Thai prime minister Thaksin Shinawatra on Friday announced that he is not interested in the junta-led reconciliation process, three days after the junta handed him a half-a-billion-dollar tax bill for his past business deal.

Dalic: We welcome possible deal between Agrokor and banks

The government welcomes the possibility of an agreement being concluded between the Agrokor food company and creditor banks, and the bill on vitally important companies is not a fallback plan but the result of the government's care for the overall economic and financial stability of Croatia, Deputy Prime Minister and Minister of Economy Martina Dalic told a press conference in Zagreb on Friday.

Croatia, China sign action plan for cooperation in agriculture

The Croatian and Chinese ministries of agriculture on Friday signed an action plan for cooperation in the field of agriculture for the period 2017-2018, the Croatian ministry said in a statement.

ZSE indices up, Agrokor shares in focus of investor interest

The Zagreb Stock Exchange (ZSE) indices on Friday rose by more than 1.8%, with stocks of the Agrokor food and retail concern being in the focus of investor interest again.

Berlin police defend handling of Berlin market attacker

Berlin police defended themselves on Friday against accusations that they stopped surveillance on Berlin Christmas market attacker despite knowing in June 2016 he was dangerous.

Croatia, creditors tailor emergency measures to save tottering giant

Croatia's tottering retail and food giant Agrokor reached an agreement with its creditors, putting its debts standby and allowing it to continue working during emergency restructuring, the Croatian branch of Austria's Erste Bank said Friday.

Agrokor's creditors say standstill agreement to go into force today

A standstill agreement regarding the Agrokor concern's existing financial obligations to banks will take effect on Friday, additional capital will be injected into the concern in the coming days and the concern will be actively restructured, which includes a change of its management, it was said on Friday after a meeting between Agrokor's suppliers and creditor banks.

Palestinians, UN slam Israel's new settlement plan

Palestinians, Israeli activists and the UN lambasted the government of Israeli Prime Minister Benjamin Netanyahu on Friday, a day after it gave the go-ahead for the first new West Bank settlement in a quarter of a century.

South Sudan rebels release three abducted foreign oil workers

South Sudanese rebels have released three foreign engineers they abducted in early March in the oil-rich Upper Nile region, Foreign Affairs Ministry official Mawein Makol Arik said on Friday.

Turkish opposition: Imprisoned party chief has gone on hunger strike

The head of Turkey's pro-Kurdish opposition party has launched a hunger strike from prison.

European leagues threaten Champions League schedule clashes

The European Professional Football Leagues (EPFL) on Friday threatened schedule clashes on Champions League matchdays in an ongoing dispute with the governing body UEFA.

Danish court revokes citizenship of IS volunteer

A Danish appellate court on Friday stripped a man of his Danish citizenship for volunteering to fight for the extremist Islamic State in Syria.

Banks and Agrokor agree on key elements of standstill agreement

Member banks of the coordinating committee of financial creditors and representatives of the Agrokor food company have in principle agreed on key elements of a standstill agreement, which is expected to be signed later today, announcing changes in the company's management team, Erste Bank said in a statement on Friday afternoon.

Syrian man on trial in Sweden; mosque attack labelled terrorism

A Syrian man went on trial Friday in the southern Swedish city of Malmo, charged with terrorism and arson after an attack last year on a building used as an assembly hall by Shiite Muslims.