At least 43 people have been killed after a man blew himself up in a truck laden with explosives at an army checkpoint in Syria's central city of Hama, according to the pro-opposition Syrian Observatory for Human Rights.

The man blew himself up inside the vehicle on Sunday on a busy road on the outskirts of the regime-held city, the Syrian state news agency SANA said.

It blamed the attack on "terrorists", the term it uses to describe opposition forces.

The Syrian Observatory said the attack targeted an army checkpoint.

"At least 31 people, including regime troops, were killed when a man detonated a truck laden with explosives at a checkpoint near an agricultural vehicles company on the road linking Hama to Salamiyeh," the Observatory said.

The Britain-based group said the death toll was likely to rise, as "there are dozens of wounded, some of them in critical condition".

In the first months after the uprising against Assad's government erupted in March 2011, Hama saw some of the largest demonstrations against his rule.

But in late summer of that year, security forces stormed the city, killing scores of people. They have held a tight grip on the city ever since.

While several other Syrian cities have been engulfed by fighting, Hama has seen only sporadic violence in recent months.

However, the surrounding province has seen some major clashes between regime troops and opposition forces.

On the diplomatic front, it was announced on Sunday that a long-delayed Geneva peace conference aimed at bringing together Syria's regime and opposition will be held on November 23.

PHOTO CAPTION

Debris and a destroyed vehicle are seen after a suicide bomber in a truck carried out an attack at the eastern entrance of Hama city, in this handout photograph distributed by Syria's national news agency SANA on October 20, 2013

Al-Jazeera