The “war is not yet over” in Syria despite the ouster of President Bashar al-Assad, the UN envoy for the country ravaged by 13 years of civil war warned today, with the UN official referring to the raging clashes in the northern part of the country between pro-Kurdish forces and pro-Turkish organizations.

“There have been major clashes in the last two weeks, before a negotiated ceasefire,” Geir Pedersen told the UN Security Council.

“A five-day ceasefire has now ended and I am deeply concerned by reports of a military escalation,” the UN envoy for Syria said, adding that “such an escalation could be catastrophic.”

The head of the Syrian Democratic Forces, dominated by Syrian Kurdish forces, announced on December 11 that a ceasefire agreement had been reached with pro-Turkish forces in Manbij, which is inhabited mainly by an Arab population and where fighting in recent days has killed 218 people.

Pedersen also referred to a meeting he had with the new leaders of Syria, who toppled the regime of Bashar al-Assad on December 8 in a lightning strike.

The UN envoy also stressed that he visited the “prisons” and “torture and execution chambers” of Sendaya prison, located 30 kilometers north of Damascus.

The UN official called for the sanctions to be lifted to allow the country, which has been devastated by more than 13 years of civil war, to rebuild. Tangible steps towards an inclusive political transition in Syria will be key to ensuring the country receives the financial support it needs, he stressed.

“There is a clear international desire to make a commitment. The needs are huge and can only be met with broad support, including the gradual lifting of sanctions,” he said.

Today, delegations from numerous countries met in Damascus with the new Syrian authorities, dominated by radical Islamists, who are trying to reassure them of their ability to rule Syria in peace.