Dozens were killed and around 200 wounded in two separate suicide attacks in a Hezbollah stronghold outside of Beirut Thursday night, Lebanese officials said.

The suicide bombers self-detonated in Burj al-Barajneh, a known hotbed for Hezbollah, a Shiite terrorist organization that is fighting to defend Bashar al-Assad’s regime in Syria.

The Islamic State has claimed responsibility for the blasts, according to reports, identifying its operatives as two Palestinians and one Syrian man.

Lebanon Prime Minister Tammam Salam called the strikes “unjustifiable” and called for Lebanese political factions to come together against “plans to create strife” between the parties.

The Associated Press reported that the first suicide bomber detonated his vest outside of a Shia mosque in the area, while the second did so while inside of a bakery. A third suicide bomber reportedly failed to carry out his act of jihad; killed by the second bomb blast before he could self-detonate.

Hezbollah, the Iran-backed terror group, has vowed a “long war” against the Islamic State “terrorists,” Reuters reports.

“They targeted civilians, worshippers, women and the elderly. It only targeted those innocent people. This is a Satanic terrorist act, carried out by apostates,” Bilal Farhat, a Hezbollah-aligned member of parliament told AP.

According to the BBC, the attack was the deadliest in Beirut since the Lebanon civil war ended in 1990.

“There were bodies on the ground, on cars, on motorcycles,” a witness said, describing the horrific scene to The Guardian. “On the floor there were bodies, flesh fragments, heads and feet.”

The U.S. State Department has condemned the attack.

“The United States strongly condemns today’s terrorist attack on civilians in the Burj Barajneh neighborhood of Beirut, Lebanon,” State Department spokesman Mark Toner said in a statement. “Today’s events are a troubling reminder of the tremendous challenges Lebanon still faces. Terrorism, such as today’s attacks, seeks to undermine the freedom and security that the people of Lebanon have worked so hard to achieve.”

“We fully support the Lebanese authorities as they conduct their investigation into this act of terror,” Toner added. “The United States reaffirms its commitment to Lebanon’s security, and will continue to stand shoulder to shoulder with the people of Lebanon in confronting terrorism.”