The United Nations says Israeli tanks burst through the gates of its peacekeeping force base in southern Lebanon after three platoons of Israeli soldiers crossed the Blue Line, Al Jazeera reports.

The UN peacekeepers said in a statement that at 4:30am (01:30 GMT), two Israeli army Merkava tanks “destroyed” their main gate and “forcibly entered the position” while peacekeepers were asleep.

“The tanks left about 45 minutes later after Unifil protested through our liaison mechanism, saying [the Israeli military] presence was putting peacekeepers in danger,” it said.

At 6:40am (03:40 GMT), peacekeepers reported several rounds being fired about 100 metres north of their position in what appeared to be an attack with some sort of chemical agent.

“Despite putting on protective masks, 15 peacekeepers suffered effects including skin irritation and gastrointestinal reactions after the smoke entered the camp. The peacekeepers are receiving treatment.”