Thousands of Syrians took part in protests against President Bashar al-Assad's regime Friday (April 20th) as 18 members of the Syrian security forces were reportedly killed, AFP reported.

The latest violence comes as UN and Arab League special envoy Kofi Annan acknowledged the situation was "not good".

"It is a very fragile ceasefire," Annan spokesman Ahmad Fawzi told reporters.

Protests took place in Deraa, the Damascus region, Homs, Hama, Idlib, Aleppo, Deir ez-Zor and Latakia, the Syrian Observatory for Human Rights said.

"Protesters called for the collapse of the regime and the ouster of President Bashar al-Assad in spite of heavy security deployment and continued shelling, gunfire and arrests by government forces," it said.

The observatory said the Khaldiyeh district of Homs was under heavy bombardment for another day. Activists in the town of Qusayr, further north, also reported heavy bombardment.

For its part, Syrian state media said 18 security personnel were killed in attacks Friday.

A blast in the southern region of Quneitra killed ten members of the security forces, state television said, attributing the blast to an "armed terrorist group".

A similar bomb attack in Karak in southern Deraa province killed five soldiers, state media said, adding that three soldiers and three civilians were killed in separate incidents elsewhere.

Meanwhile, the United Nations said a $180 million draft plan for delivering aid to Syria has been drawn up and is awaiting the green light from Damascus.

Donors are ready with their cash to provide food, medical and other supplies, said John Ging, director of operations for the UN Office for the Coordination of Humanitarian Affairs (OCHA).

"We were able to access all areas that we needed to access to assess the situation and get a more accurate understanding of the needs," Ging said.

"We have shared with the forum the draft response plan that has been developed by UN agencies on the ground. That plan amounts to $180 million which is added to the regional refugee response plan of $84 million. Our donor community is fully aware of what we have planned. Now it is a question of implementing those plans," he said.