Lebanon on Friday indicted two Syrian intelligence officers it accused of involvement in a deadly 2013 double bomb blast in the city of Tripoli, a judicial source said.

The double bombing on 23 August, 2013, killed 45 people, and a series of indictments have already been handed down against Lebanese and Syrians accused of involvement.

The indictment names Captain Mohamed Ali Ali, an official in the Palestine branch of Syria's intelligence services, and Nasser Jouban, an official in Syria's political security branch.

The two men, neither of whom is in custody, are accused of helping to prepare the attack, placing explosives in cars and assigning a Lebanese cell to carry out the bombing, which also wounded hundreds.

The attacks targeted two Sunni mosques in Tripoli, which has frequently experienced tensions between Sunnis and Alawites who belong to the same religious minority as Syrian President Bashar al-Assad and tend to support his government.

The indictment alleges the attacks also involved other high-ranking Syrian officials, who are accused of directing Ali and Jouban to organise them.

The blasts in the northern city were the deadliest attack in Lebanon since the country's 1975-1990 civil war and raised fears that the conflict in neighbouring Syria could be inexorably seeping across the border.

Lebanon's political landscape is largely divided between parties that back Assad and those who support the uprising against him that began in March 2011.

The division has stoked tensions in Lebanon and created a political stalemate that has left the country without a president for more than two years.

Lebanese justice minister Ashraf Rifi said on Friday that he would ask the government to expel Syria's ambassador to the country and cut diplomatic ties with Damascus, the Reuters news agency reported.