A car bomb exploded outside the police headquarters in a town north of the Syrian capital, killing at least 13 people including 10 policemen, activists said on Monday.

The Britain-based Observatory for Human Rights said the blast took place overnight in the town of Deir Atiyeh, some 80 kilometers (50 miles) north of Damascus. One child was among the dead, the Observatory said.

Syria’s state news agency confirmed the attack, but said a suicide bomber detonated an explosives-laden car in a residential area of the town, causing an unknown number of casualties. It said “terrorists” were behind the blast a government term for rebels fighting to topple President Bashar Assad’s regime.

There was no immediate claim of responsibility, but radical Islamic groups, including those with links to al-Qaeda, frequently target Syrian government institutions, security installations and troops with car bombs and suicide attacks.

Last month, a Syrian branch of al-Qaeda known as Jabhat al-Nusra, claimed responsibility for multiple suicide attacks on security compounds in Damascus that killed at least five people.

The Nusra Front and other Islamic extremist groups have been the most effective fighting force on the opposition side in the past year, spearheading many of the rebel offensives that have captured military bases, towns and villages.

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