BEIRUT — Two visiting U.S. senators condemned a double suicide bombing that ripped through a Shiite stronghold of the Lebanese capital Wednesday, saying they were concerned about the spillover effects of Syria’s civil war.

Two bombers blew up their cars near an Iranian cultural center in Beirut, killing at least four people and wounding more than 100.

An al-Qaida-linked group said the attack was retaliation for Hezbollah’s involvement in the Syrian war alongside President Bashar Assad’s forces.

The explosions occurred as Sens. Tim Kaine of Virginia and Angus King of Maine were in Beirut. The senators are on a weeklong trip that includes Israel and the West Bank and Egypt.

“We condemn the violence and we have deep condolences for the victims and families and feel for the Lebanese people,” Kaine, a Democrat, said.

The senators spoke after meeting with Lebanese President Michel Suleiman and Prime Minister Tammam Salam, who formed a Cabinet last week.

King, an independent and member of the Senate Armed Services and Intelligence committees, said the focus of the visit is U.S. humanitarian aid to Lebanon to deal with the influx of refugees from Syria.

“It’s a problem that I’m afraid is not going to get better in the immediate future and … the only long-term solution is a cease-fire and ultimately a political settlement in Syria,” he said.