Lebanon said 12 people have been killed, including an eight-year-old girl and an 11-year-old boy, after handheld pagers used by members of the armed group Hezbollah to communicate exploded across the country.

Iran’s ambassador to Lebanon was among 2,800 others who were wounded by the simultaneous blasts in Beirut and several other regions.

Hezbollah, which is backed by Iran, said the pagers belonged “to employees of various Hezbollah units and institutions” and confirmed the deaths of eight fighters.

The group blamed Israel for what it called “this criminal aggression” and vowed that it would get “just retribution”. The Israeli military declined to comment.