They worked to evacuate residents from the upper floors using a ladder.
Hassan Jaber, who lives in a nearby building, said he was wounded in the hand and leg.
“I went out to throw out the rubbish, opened the door of the lift and the strike hit” and he was propelled to the ground, he said.
“It was such a big shock,” he said, bewildered.
The atmosphere was tense after Hezbollah and the Lebanese army set up a security cordon around the area.
Hezbollah said it was cancelling a press conference planned for Friday, “in view of current developments”.
