Israel said it struck targets in Lebanon on Monday evening after vowing to retaliate for an attack by Hezbollah on a military post, with both sides accusing each other of violating last week’s ceasefire.

At least nine people were killed by Israeli strikes on two southern Lebanese villages, according to the country’s public health ministry.

The Israel Defense Forces (IDF) said it struck Hezbollah targets and infrastructure “throughout Lebanon”, while reiterating its commitment to the ceasefire agreement.

Hezbollah said it was responding to Israeli “violations” and said it carried out a “defensive warning” strike, firing mortars at an Israeli army position in an area occupied by Israel.

Israel said there were no injuries in Hezbollah’s strikes on the Mount Dov area – a disputed region on the Israel-Lebanon border known internationally as Shebaa Farms.

Israeli Prime Minister Benjamin Netanyahu described the Hezbollah attack as “a severe violation of the ceasefire”, vowing that Israel would “respond forcefully”.

When the ceasefire deal was first announced, Netanyahu said his country would not hesitate to strike if Hezbollah broke the terms.

Monday’s violence is an indication of the fragility of the recently agreed truce, aimed at ending 13 months of conflict between Israel and Hezbollah.

Last week, the US and France said the agreement would “cease the fighting in Lebanon, and secure Israel from the threat of Hezbollah and other terrorist organisations operating from Lebanon”.

Hezbollah has been given 60 days to end its armed presence in southern Lebanon while Israeli forces must withdraw from the area over the same period.