Lebanon’s army has arrested four people suspected of having links to terrorist activity. Two Syrians, one Lebanese man and a fourth man of unidentified nationality were arrested in the suburbs of Beirut this weekend, officials said. Security forces have amplified counterterrorism efforts after two suicide bombings claimed nine lives in northern Lebanon last week.

The army released details of the arrests in a statement cited by the Daily Star newspaper in Lebanon. The two Syrians, Ahmed Rahmo Sattouf and Ghossoun Ibrahim al-Hussein, and their Lebanese associate, Mohammad Ali Shukkor, were arrested in the Beirut suburb of Haret Hreik. Officials reportedly seized a number of counterfeit checks that were in Shukkor’s possession.

A military unit also raided the apartment of a man identified as Ahmed Kahwagi, who was reportedly tied to several shooting incidents and terrorist activities, the statement said.

Lebanese security forces have been ratcheting up counterterrorism operations after twin suicide bombings in a cafe in the northern city of Tripoli killed nine  and injured 30 Jan. 10. “The army has increased its preemptive operations against terror groups, which has resulted in thwarting a series of suicide attacks in the country,” a senior military official told the Daily Star.

The army arrested Friday two suspected members of a terrorist ring in Tripoli and seized a number of grenades, military equipment, explosive belts and guns, the Daily Star reported. And security forces raided Monday a block of the Roumieh prison that was reserved for militants with alleged terror links, saying detainees had been in communication with suspects behind the two suicide bombings. Authorities have cited the ongoing conflict in neighboring Syria as a cause of escalated tensions and security threats in Lebanon.