BEIRUT: Rebels and regime troops clashed in the Damascus district of Qadam on Wednesday as at least nine people were killed in violence across Syria, the Britain-based Syrian Observatory for Human Rights said.

In the commercial hub of Aleppo, two soldiers were killed when rebels attacked a checkpoint overnight, it said, adding that loud blasts were heard in the northern city on Wednesday.

The Observatory also reported an attack in the northwestern province of Idlib on a bus transporting soldiers, killing as many as 11 troops although the exact number was impossible to verify.

Anti-regime activists say much of Idlib has been “liberated” from the regime's control.

“That doesn't mean the violence stops, it just means they shell us from further away,” an activist in Idlib who identified himself as Nour Eddine al-Abdou told AFP via Skype, adding he had no information on the bus attack.

“When they start shelling, which is usually at night, women, children and the elderly fill the underground shelters,” Abdou said. “It's violent and frightening, but we feel some joy because we know victory is possible.”

Of those killed on Wednesday, three were civilians and four were rebel fighters, apart from the two deaths in Aleppo and the Idlib attack, the Observatory said.

The Observatory said 82 people were killed in violence on Tuesday: 30 civilians, 26 soldiers and 26 rebels.

According to estimates from the Britain-based monitoring group, more than 17,000 people have been killed since the uprising erupted in mid-March last year, at first with peaceful protests.

It is not possible to independently verify death tolls since the United Nations at the end of 2011 stopped compiling such figures.