One Palestinian and five Syrian suspects were arrested by Lebanese authorities for potential involvement in the pair of suicide bombings that killed 43 and injured more than 200 in central Beirut, a senior security source told Reuters Saturday. The blasts occurred on Thursday within 5 minutes and 100 feet of one another. They occurred in the Ain al-Sikke neighborhood in Burj al-Barajneh, a busy residential and commercial district known for its heavy Hezbollah presence.

“Within 24 hours the network was arrested in the fastest uncovering of a bombing incident in the country,” the source told Reuters.

In a statement posted online by supporters of the Islamic State group, it seemed as though ISIS claimed responsibility for the attacks. One had detonated a bike rigged with explosives while another blew himself up as onlookers gathered. Reuters also reported that a third suicide bomber was killed before he could detonate his own explosives.

Beirut bombings A Lebanese army soldier secures the area as blood stains are seen on the ground at the site of the two explosions that occurred Thursday in the southern suburbs of the Lebanese capital Beirut, Nov. 13, 2015. A source told Reuters Saturday Lebanese authorities have arrested five Syrians and a Palestinian in the bombings. Photo: REUTERS/Aziz Taher

The twin bombings are the first attacks the Hezbollah stronghold has seen in nearly 10 months. The Hezbollah movement sent hundreds of fighters to support Syrian President Bashar Assad’s forces in the conflict, and the twin bombings were seen as a warning that ISIS wants to bring the Syrian battle into Lebanon.

Lebanon’s Hezbollah leader Sayyed Hassan Nasrallah said the detainees had been arrested under suspicion of being involved in the bombings, Reuters reported. Nasrallah did not confirm if a Palestinian suspect had been among those arrested, and he discouraged his followers from retaliating against ordinary Syrians and Palestinians in the bombings’ aftermath, noting the goal of radical fundamentalists was to stir discord among Sunnis and Shiites.