A series of bombings claimed by Islamic State militants that hit government-held areas in central Homs province and near the Syrian capital Damascus a day ago has killed 184 people, a monitoring group said Monday.
Rami Abdel Rahman, head of the Syrian Observatory for Human Rights, told dpa that the Sunday attacks were the deadliest one-day bombings since the Syrian uprising erupted in 2011.
The Britain-based watchdog said 120 people, including 75 civilians, were killed after two suicide attacks and two car bombs rocked Sayeda Zeinab, a Shiite area south of the capital Damascus.
In Homs, the death toll stood at 64, among them 39 civilians, after two car bombs rocked a regime-held area in the city's al-Zahara district, the Observatory said. The neighborhood's residents belong in large part to the Alawite sect of Syrian President Bashar al-Assad.
Statements in the name of the Islamic State movement, posted on social media, claimed responsibility for both attacks.
Dpa was not able to authenticate the claims, but they were consistent with previous statements by the group, including claims of responsibility for three other deadly attacks in the same areas since December.
The attacks came as world powers discussed ways to implement a Syrian ceasefire in the coming weeks.
US Secretary of State John Kerry said Sunday that he had reached a "provisional agreement in principle" with Russian Foreign Minister Sergei Lavrov on terms for a truce.
In Saudi Arabia, members of the opposition's Higher Negotiations Committee told dpa they were due to meet Monday to discuss the proposed ceasefire after rebel representatives gave their "initial approval".
A cessation of hostilities by Friday was proposed on February 12 by world powers meeting in Munich, Germany. Part of the plan was also to ensure access for humanitarian aid to besieged areas in Syria.