Syrian forces pounded opposition targets across the country on Friday, less than a week before a United Nations-backed deadline for a cease-fire.

Activists say fresh shelling erupted in areas including the flashpoint Homs region and Damascus suburbs. The Syrian Observatory for Human Rights says at least 24 people were killed, most of them civilians. The attacks came as tens of thousands of Syrians reportedly took part in anti-government protests, according to opposition counts.

On Thursday, U.N. Secretary-General Ban Ki-moon warned that Syria's conflict was escalating and attacks by government forces on civilian areas showed no signs of slowing, despite assurances from Damascus that it had begun withdrawing its troops from major cities.

Mr. Ban told the General Assembly that Syrian “cities, towns and villages had been turned into war zones.” He urged President Bashar al-Assad “to show leadership and vision” and keep his pledge to end violence by April 10.

Mr. Assad agreed to the U.N.-backed peace plan on March 25, but international peace envoy Kofi Annan said in a video from Geneva that the Syrian government has made little progress on ending its yearlong crackdown on dissent.

A small technical team representing Mr. Annan arrived in Damascus Thursday to begin laying the groundwork for a potential U.N. monitoring mission.

The Reuters news agency reports the Free Syrian Army says it has met with Mr. Annan's delegation. The opposition group pledged to stop its fighting if Syrian forces withdraw before next week's deadline.

Syria blamed much of the violence on “terrorists” it says are supported by “Arab and Western countries.” The state-run SANA news agency said Friday that terrorist acts increased after Damascus reached an agreement on Mr. Annan's peace plan.

Growing numbers of Syrians fleeing violence have poured into neighboring Turkey. Turkish officials say more than 2,800 Syrian refugees have arrived in the past two days.

Refugee Omar Sunni says he fled an intense government assault in Idlib province.

“Helicopters bombed the area. The roads are destroyed. Homes are destroyed. We can't bring the wounded. We could not bring the wounded because we could not reach the area because it is still being bombed.”

U.N. refugee agency representative Metin Corabatir told VOA on Friday the rising number of refugees may become a financial burden to Ankara.

“As the numbers go up, the financial cost of having these people, of meeting their basic needs, is increasing. But, at the moment, Turkey declared that it is ready to continue to provide all kinds of assistance.”

Turkish Foreign Minister Ahmet Davutoglu called U.N. chief Ban on Friday to express concern about the growing tide of refugees.

The Syrian government has promised to stop all military action by April 10. Under the terms of the Security Council statement passed Thursday, the opposition is supposed to lay down its arms within 48 hours after the government fulfills its promise.

The United Nations says more than 9,000 people have been killed in Syria since the uprising against Mr. Assad began 13 months ago.