The Turkish government's sphere of influence no longer runs on the other side of the river through the south-eastern city of Nusaybin. An explosion has ripped a hole in the bridge leading to the Abdul Kadir Pasha quarter and the wreck of a tanker lies at an angle across the road.
Fighters from the Patriotic Revolutionary Youth Movement (YDG-H), an offshoot of the banned Kurdistan Workers' Party (PKK), are dug in on the other side awaiting renewed attacks from Turkish security forces.
The bullet holes in the burnt out tanker are a reminder of the recent fighting. Last month, the Turkish army launched an offensive against the YDG-H in Kurdish-dominated cities in the region, imposing curfews lasting for weeks.
"In no democratic country a government tolerates the presence of armed groups and terrorists in some parts of the country," Prime Minister Ahmet Davutoglu said shortly before paying a visit to Berlin on Friday.
The last curfew - the sixth since the summer - was lifted in Nusaybin, a city of some 100,000, shortly before Christmas, even though the security forces had failed to root out the YDG-H completely.
Five of the city's 15 quarters are under their control and beyond the reach of the state's security forces, according to the city authorities. Army and police armoured vehicles patrol the streets of the other quarters.
Crossing the bridge into Abdul Kadir Pasha, a Kurdish guide says that the "liberated zone" is now being entered. The YDG-H has strong support in the contested areas, with many Kurds seeing the young fighters as protecting them against the Turkish forces.
The Turkish government regards the YDG-H as terrorists.
Paving stones have been torn up on the other side of the bridge to build barricades. The YDG-H has sprayed its logo on walls in the quarter, along with warnings. "There is no excuse for treason," is one slogan.
Huge sheets of blue plastic are stretched across the roads to obscure the line of sight for any army snipers.
A group of YDG-H fighters are tearing up yet another street, the 10 young men and four women wearing a motley assortment of military trousers and boots, joking with each other as they work. There is music playing and the atmosphere is relaxed.
They dig trenches with pickaxes and shovels, filling the earth into sacks for heaving onto the barricades of paving stones.
The YDG-H headquarters lies a few streets away. The commander goes by the name of Omer Aydin. He sits smiling and chain-smoking with his comrades in a courtyard around a stove.
Pictures of martyrs adorn the walls, along with the portrait of PKK head Abdullah Ocalan, who has been held by the Turkish authorities since 1999.
A couple of shots ring out. "It's nothing," Aydin says. "Our friends are building barricades and the soldiers are shooting at us."
President Recep Tayyip Erdogan has sworn to fight the PKK - listed as a terrorist organization by the United States and the European Union - "to the end."
A few days ago, he called on the YDG-H to lay down its arms, warning that those who failed to do so would pay the price for "treason."
"I call on the young people in the terrorist organization to turn away from this mistake before it is too late," Erdogan said, adding that those giving themselves up to the police would be well treated.
Aydin has no confidence in this pledge. "The state aims to destroy us," he says. "We didn't start this, but no one reacted as Kurds were being massacred."
Taking Spain's Basque country as its example, the YDG-H is calling for "democratic autonomy" for Turkey's large Kurdish minority concentrated in the south-east.
Young Kurds like Aydin initially fought with Molotov cocktails and stones, but those days lie in the past, he says. "Since the attacks by the state we have laid hands on weapons," he says.
Aydin refuses to say where the arms come from, pointing out that after decades of conflict, "there is nothing easier than finding weapons in Kurdistan."
He also refuses to put a number on the fighters available to the YDG-H. He insists that the militant organization abides by the Geneva Convention and does not make use of child soldiers.
"We do not arm anyone under 18," he says, although from the age of 16, youth are allowed to help, for example by building barricades.
Aydin describes the YDG-H as "organized and disciplined" and operating independently of the PKK, although Western security experts have cast doubt on this claim.
He is certain that the Turkish army will attack in Nusaybin once the large operations in progress against the YDG-H in the Sur quarter of Diyarbakir and in the city of Cizre are over.
How long the YDG-H, which Aydin claims has only assault rifles, rocket-propelled grenades and homemade explosives in its arsenal, will be able to stand up to the second-largest army in NATO, is questionable.
"In Sur we resisted for 50 days," he says. "Isn't that a victory of a kind?"