Updated

The Syrian government sent troops backed by tanks into rebellious areas Monday, hunting down activists and torching their homes and bulldozing others, opposition groups said.

At the United Nations, international envoy Kofi Annan set an April 10 deadline for full compliance with a peace plan to end the violence in Syria. He also told the Security Council at a closed door briefing Monday that Damascus has agreed to withdraw its troops from cities by that date, reversing its previous refusal to implement the measure, diplomats said.

The opposition is deeply skeptical of Assad's intention to abide by his promises, describing it as another attempt to buy time while government troops continue their assault on the rebels.

Several times over the past few months, the Assad regime has agreed to a peace plan, only to ignore it on the ground. Most recently, it signed on to a plan by Annan, but then rejected his appeal for the government to lay down its weapons before the rebels did.

Also, several months ago Syria accepted an Arab League plan to send monitors to work for a cease-fire, but the mission collapsed in violence.

Activists on Monday said fierce clashes were taking place in the central region of Homs, after which rebels took control of the national hospital in the Jouret al-Shayah district. Human rights groups and the opposition have accused government forces of abusing and torturing wounded activists in the hospital in previous months.

The Local Coordination Committees and the British-based Syrian Observatory for Human Rights said rebels found around 70 unidentified bodies in the hospital refrigerators, apparently belonging to people killed in earlier fighting.

In the south, dozens of tanks surrounded the town of Dael early Monday before troops pushed in, shooting holes in rooftop water tanks and targeting dozens of activists' houses, torching some and bulldozing others, said local activist Adel al-Omari.

"They focused on the activists. They have their names and have been tracking them," al-Omari said, speaking by telephone from a garden in Dael where he was hiding. "They went in and spread fuel to totally burn them down."

Activists said government troops also set fire to homes in the northwestern village of Haas, where one activist said they killed seven people in one house.

"The regime forces have pretty much stopped arresting people," activist Fadi al-Yassin said via Skype. "They either kill them right away or keep them for one day to get information and then kill them."

The Britain-based Syrian Observatory for Human Rights, which relies on an activist network in Syria, said at least 8 houses were burned in Haas and that two civilians and five rebel fighters were killed, among at least 24 killed nationwide.

The activists' claims could not be independently verified. The Syrian government rarely comments on specific incidents and bars most media from working inside the country.

The fresh violence underlined how little international diplomacy has curbed the crisis in Syria, which began more than a year ago with largely peaceful protests calling for political reforms. Assad's government has unleashed a punishing crackdown to try to crush the spreading dissent, prompting many in the opposition to take up arms and fight back. The U.N. says more than 9,000 people have been killed.

On Sunday, more than 70 countries, including the United States, pledged to send millions of dollars and communications equipment to dissidents inside Syria, signaling a growing belief that diplomacy and sanctions will not push Assad from power.

Participants at the international conference in Istanbul where the pledges were made said Saudi Arabia and other Gulf Arab countries were creating a fund to pay Syrian rebels and soldiers who quit the regime to join the uprising.

Participants confirmed the Gulf plan on condition of anonymity since its details are still being worked out, and it remains unclear whether the funds -- which could be several million dollars per month -- will also buy weapons.

Rebel fighters bemoan their inferior arms and say only powerful munitions will allow them to face Assad's large, professional army.

Annan has been pushing a six-point plan to end the Syrian crisis that includes an immediate, daily two-hour halt to fighting so aid can reach embattled civilians. It also calls for an overall cease-fire so all parties can discuss a political solution.

Annan told the U.N. Security Council that he has set an April 10 deadline for full compliance with the plan, according to a diplomat who listened to the briefing and spoke on condition of anonymity because it was closed.

The Syrian government's stance was reminiscent of a failed mediation attempt by the Arab League around the start of the year. Assad agreed to that plan to pull tanks and artillery out of cities and allow in foreign monitors in to assess compliance. But the mission ended in failure, and Assad ultimately did not comply with the terms of the agreement he had signed on to.

Annan has asked government troops to withdraw first in a "gesture of good faith."

Russian Foreign Minister Sergey Lavrov also said Monday that Syrian forces must withdraw first, followed quickly by opposition forces.

U.S. Ambassador Susan Rice expressed skepticism about Syria's commitment, saying that Damascus has made and broken promises over many months.

"So the United States, for one, would look at these commitments and say, yet again, the proof is the actions, not in the words," she said.

The president of the International Committee of the Red Cross, Jakob Kellenberger, arrived in Syria Monday for a two-day visit in a bid to improve access for humanitarian workers.

Despite growing international condemnation, Russia and China have stood by Assad, twice protecting him from censure by the Security Council.