A suicide bombing struck a coffee shop Saturday night in the northern Lebanese city of Tripoli, killing at least seven people and wounding more than 30, security officials and the Red Cross said.

Syria’s al-Qaida-linked Nusra Front claimed responsibility on Twitter for the blast in Tripoli’s predominantly Alawite neighborhood of Jabal Mohsen, saying it was a twin suicide attack.

George Kitane, the head of paramedics at the Lebanese Red Cross, told the private satellite station al-Jadeed that seven people were killed and 36 wounded in the attack.

The state-run National News Agency said the attack killed nine people and wounded more than 35, citing its local reporter for the casualty figures. It said two suicide bombers carried out the attack, identifying them as Lebanese citizens from the nearby poor neighborhood of Mankoubeen.

A Lebanese army statement said a single suicide bomber attacked the cafe at around 7:30 p.m. (1730 GMT, 12:30 p.m. EST). It said military police would investigate the bombing.

Security officials, speaking on condition of anonymity as they weren’t authorized to talk to journalists, said earlier that the attack began with a grenade tossed inside the cafe, followed by a single suicide bomber.

Tripoli has been relatively quiet recently after years of tension between its majority Sunni population and its Alawite minority. Embattled President Bashar Assad in neighboring Syria is an Alawite and support for him in Tripoli has sparked violence there before. Most of the Sunnis in Tripoli support the predominantly Sunni Syrian rebels trying to overthrow Assad.

Lebanon has seen a series of attacks and suicide bombings since the conflict in Syria, which has killed more than 200,000 people, began nearly four years ago. Saturday’s attack was among the deadliest to hit the country in the past year.

Lebanon’s al-Qaida-linked group, the Abdullah Azzam Brigades, has claimed responsibility for some of the attacks. It has warned that attacks will continue as long as the militant Shiite Hezbollah group takes part in Syria’s civil war alongside Assad’s military. SAPA