Syrian government forces have launched military assaults in different parts of the country, activists say, as key ally Russia has said that Damascus is making "a lot of mistakes" in handling the unrest sweeping the country.

Opposition activists on Wednesday said army troops shelled three neighborhoods in central city of Homs, a day after at least 14 people were killed in heavy bombardment.

The districts under attack, al-Qosour, al-Khalidiya and al-Bayada, are located adjacent to one another in northern Homs.

Hadi al-Abdallah of the Syrian Revolution General Commission activist network told Al Jazeera that the neighborhoods are crowded with people who fled Bab Amr, the area that government troops took over from opposition fighters after a fierce offensive last month.

"Four or five families are crammed into each house. People are also sheltering in mosques and unfinished buildings," he told the AFP news agency in a separate interview.

The Syrian Observatory for Human Rights (SOHR), a UK-based rights group, reported that at least five people had been killed and dozens more wounded during Wednesday's shelling in al-Khalidiya.

The Observatory said four soldiers were also killed on Wednesday in the Sultaniyeh district of the city, while four civilians had been also killed in the town of Talbisseh, in the province of Homs.

It said that at least 40 people, 32 of them civilians, had been killed in army operations and clashes with deserters across the country on Wednesday.

Artillery was also reported to have targeted the rebel town of Rastan, north of Homs city, and shelling at the ancient Apamea castle at Qalat Mudiq, near Hama.

Also on Wednesday, two large suburbs of Damascus came under heavy tank bombardment following renewed attacks by opposition fighters on forces loyal to President Bashar al-Assad.

Artillery and anti-aircraft gun barrages hit the suburbs of Harasta and Irbin, retaken from rebels by Assad's forces two months ago, and army helicopters were heard flying over the area, on the eastern edge of the capital, the activists said.

Elsewhere, opposition fighters fled the eastern Syrian city of Deir al-Zor in the face of a fierce army assault.

"Tanks entered residential neighborhoods, especially in southeastern areas of Deir al-Zor. The Free Syrian Army pulled out to avoid a civilian massacre," a statement by the Deir al-Zor Revolution Committees Union said on Tuesday.

Activist Osama Mansour said the fighters lacked guns and ammunition.

"They knew they could not hold control of the neighborhoods, so they decided to stop fighting, knowing that the regime would bring in heavy weapons and kill many civilians,'' Mansour said.

The lightly-armed Free Syrian Army retreated across the country in recent weeks, with the army using heavy armor to chase them from towns and cities.

The official Syrian news agency SANA reported that the funerals of seven security force members killed in the fighting were also held on Wednesday.

Reports from Syria cannot be independently verified because of strict reporting restrictions imposed by the Syrian government.

Diplomatic setback

But as Assad made advances on the ground, he appeared to suffer a setback on the diplomatic front, with the UN Security Council unanimously adopting a statement calling for the government to back a six-point UN plan to end the violence.

Key Syrian ally Russia backed the statement, and has also adopted a new, sharper tone after months of publicly standing by his government.

"We believe the Syrian leadership reacted wrongly to the first appearance of peaceful protests and ... is making very many mistakes," Sergei Lavrov, the Russian foreign minister, told local radio station Kommersant-FM.

"This, unfortunately, has in many ways led the conflict to reach such a severe stage."

Lavrov also spoke of a "future transition" period for Syria but continued to reject calls from most Western and Arab states for Assad to resign, saying this was "unrealistic".

It was not immediately clear if the change in language would translate into a tangible difference in the way the divided international community might deal with the crisis.

Opposition fighters 'abuses'

The uprising against Assad started in March 2011. His security forces quickly cracked down on dissent, attacking protesters with tanks, snipers and pro-regime thugs.

The UN says more than 8,000 people have been killed, many of them unarmed protesters.

The conflict has grown more militarized as many in the opposition have taken up arms to protect their towns and attack regime forces.

On Tuesday, Human Rights Watch (HRW), an international human rights group, accused opposition rebels of kidnapping, torturing and executing members of the security forces, pro-government armed gangs and other government supporters.

HRW called on Syrian political opposition leaders to condemn the abuses.

"The Syrian government's brutal tactics cannot justify abuses by armed opposition groups,'' Sarah Leah Whitson, the Middle East director at HRW, said

"Opposition leaders should make it clear to their followers that they must not torture, kidnap, or execute under any circumstances.''

The Syrian state news agency, meanwhile, reported that several law enforcement officials and civilians were killed in a "suicide" attack in the restive southern province Deraa on Tuesday.

"A number of law enforcement members, several civilians were martyred Tuesday when a suicide terrorist exploded a booby-trapped car" targeting security forces on the Al-Musefra-Busra road in the Daraa countryside, it said.

"The blast caused big damages in some surrounding buildings" and left behind a two-metre crater, the agency said in English, but without giving any specific casualty toll.

The SOHR confirmed that the blast took place, but was not able to provide details.

PHOTO CAPTION

Demonstrators protest against Syria's President Bashar Al-Assad in Kafranbel near Idlib March 18, 2012.

Aljazeera