Multiple explosions hit the northern Syrian city of Aleppo on Friday, one near a building belonging to security forces, killing dozens and wounding more than 100, according to government officials.

The state broadcaster quoted the Health Ministry as saying 28 people had been killed and 235 wounded. It said the explosions were caused by suicide car bombers and aired graphic footage of the destruction, which it said was the work of "armed terrorist gangs."

Aleppo, Syria's second-largest city and a main commercial hub, has been mostly quiet in the 11-month uprising in Syria, in which rights groups estimate more than 6,000 people have been killed.

Friday's were the deadliest explosions since two suicide bombings in Damascus - one in January that killed 26 and another in December that killed 44.

Homs attack

Meanwhile, six days of relentless shelling and sniper attacks have killed at least 400 people in the Syrian city of Homs, activists say, while residents foresaw no relief as government tanks amassed outside the opposition neighborhoods on Friday.

At least 83 people were killed across the country on Thursday, more than 50 of them in Homs, according to the London-based Syrian Observatory for Human Rights. Activists have been relaying death toll reports to foreign media because of Syria's restrictions on the press.

"Snipers are on all the roofs in Baba Amr, shooting at people," Abu Muhammad Ibrahim, an activist in Homs, told The Associated Press by phone on Thursday, referring to one of the hardest-hit neighborhoods in the city. "Anything that moves, even a bird, is targeted. Life is completely cut off. It's a city of ghosts."

Medical workers have reportedly used loudspeakers to call for blood donations and medical supplies, while some areas have been without power for days.

"The bombardment has not eased, day or night," Ibrahim added.

Few diplomatic options

Diplomatic efforts to halt the violence have so far been fruitless, after Russia and China on Saturday vetoed a UN Security Council resolution condemning the government violence.

On Friday, Russia fanned the flames by accusing Western states of arming the rebels and giving them advice, partly in response to two US lawmakers urging the US government to support the rebels.

Several Western and Arab nations have recalled their ambassadors from Damascus and the European Union is reportedly considering sanctions against the government of President Bashar Assad. But possible military intervention akin to NATO actions in Libya last year, when the bloody rebellion turned into an even bloodier civil war, is not currently being discussed - limiting the international community's options for trying to stop the bloodshed.

Military defectors grouped under the loosely-organized Free Syrian Army have questioned how long government forces can hold out, saying the brutality of the government onslaught has led more troops to join the rebellion.

acb/ng/pfd (AP, AFP, Reuters)