BEIRUT (AP) -- Syrian troops clashed with army defectors and shelled rebellious districts in the central city of Homs Wednesday, killing at least 11 civilians a day after the government claimed it had begun a troop withdrawal ahead of the deadline to implement an international truce plan.
Activists said the latest deaths included a man and his son who died in gunfire during fighting in the Qusour district of Homs. They said the renewed violence proved President Bashar Assad's regime was not serious about implementing the cease-fire brokered by former U.N. chief Kofi Annan.
Russia, a key ally of Assad, warned other nations not to arm the Syrian opposition, saying it would only escalate hostilities. Saudi Arabia and Qatar, two Sunni-ruled nations, have backed the idea of arming the rebels fighting government forces, but the West remains opposed. Western nations however did create a multimillion dollar fund for the opposition at a meeting in Istanbul.
"Even if they arm the Syrian opposition to the teeth, it won't be able to defeat the Syrian army," Russian Foreign Minister Sergey Lavrov said. "The carnage will go on for many years."
Assad agreed earlier this week to an April 10 deadline to implement the plan put forward by international envoy Kofi Annan. It requires regime forces to withdraw from towns and cities and observe a cease-fire. Rebel fighters are to immediately follow by ceasing violence.
Opposition activists charged Tuesday that the regime was racing to crush opponents ahead of the cease-fire deadline by carrying out intense raids, arrests and shelling.
A Syrian government official said Tuesday evening that troops had already started pulling out of some calm cities, a week ahead of the April 10 deadline.
"Forces began withdrawing to outside calm cities and are returning to their bases, while in tense areas, they are pulling out to the outskirts," the government official told The Associated Press in Damascus without saying when the withdrawal began. He spoke on condition of anonymity because he was not authorized to talk to the media.
In Homs, a bastion of dissent against Assad's regime, opposition figure Mohammed Saleh said a series of loud blasts rattled windows in his home, and heavy machine gun fire was heard across parts of the old city.
He said it was not clear what caused the blasts. In recent days, armed defectors known as the Free Syrian Army have taken control of the national hospital in the Jouret al-Shayah district and two other government buildings.
"There is no sign of any withdrawal or calm in Homs," Saleh said. "The situation is just as bad as it has been for the past few months."
Amateur videos posted online by activists showed thick flames and black smoke billowing from above what appeared to be a residential building in the Qusour district of Homs. Another video showed a huge fire and explosion behind the minaret of the Dar al-Salam mosque in the Qarabees district.
The British-based Syrian Observatory for Human Rights said a man and his son were among seven civilians killed in fighting in Qusour neighborhood. Three others were killed in shelling of the town of Talbiseh in Homs province and one in Deir Baalba.
A 50-year-old former political detainee identified as Ahmad al-Othman and his 40-year-old brother Adnan, a lawyer, were killed overnight when troops fired on their car from a machine gun mounted on a tank in Idlib province, according to activists in the northern area and the British-based Syrian Observatory for Human Rights.
Their deaths along with an elderly men in Idlib brought the civilian deaths Wednesday to 13, according to the Observatory.
In the Damascus suburb of Douma, activist Mohammed Saeed said troops carried out more raids and arrests on Wednesday. He said tanks and checkpoints remained in place and reported overnight clashes in the suburb of Kisweh and Moaddamiyeh.
"It is impossible for the regime to withdraw from towns and cities because if it did, we would be in Damascus on the next day," Saeed said.
The opposition has blasted Annan's plan as too little, too late and are particularly angry that it does not call for Assad to leave power -- the central demand of the uprising. They suspect Assad will manipulate the plan and use it to stall for time while his forces continue to crack down.
The Syrian government has not commented publicly on the April 10 truce deadline. It has accepted other peace plans in recent months only to ignore them on the ground. An Arab League effort that included sending in monitors to promote a cease-fire collapsed in violence in November.
Syria's uprising started in March 2011 with peaceful protests calling for political reforms, inspired by other Arab Spring revolts around the region. Assad's forces used deadly force to try to crush the spreading dissent, and many in the opposition took up arms to defend themselves. The U.N. says more than 9,000 people have been killed since the revolt began.
Relentless government shelling of rebellious areas and frequent clashes with rebels have taken a high toll on Syria's civilians, and the International Committee of the Red Cross is pressing Syria to give aid workers access to embattled areas.
ICRC president Jakob Kellenberger and his team toured the southern province of Daraa, birthplace of the Syrian uprising. ICRC spokesman in Syria Saleh Dabbakeh said two trucks loaded with humanitarian aids and around 1000 baskets of staples including rice, sugar, beans and canned food were accompanying the mission.
The United States said Tuesday that the U.N. Security Council must respond urgently and seriously if Syria fails to keep its pledge to halt offensive military operations by Annan's deadline next week.
U.S. Ambassador Susan Rice told reporters that Syrian forces have been continuing offensive operations and the United States "is concerned and quite skeptical that the government of Syria will suddenly adhere to its commitments."
"What we have seen since April 1 is not encouraging," Rice said.