Lebanon's Hezbollah group says its top commander Mustafa Badreddine has been killed in an attack in Syria. Its being seen as the biggest blow to the Iranian-backed organisation since its military chief was killed in 2008.

Badreddine was one of the highest ranking officials in the group. The U.S. government believed he was responsible for Hezbollah's military operations in Syria. Reports say he was killed in a big explosion at one of the group's bases near Damascus airport.

An investigation is now underway into the cause of the blast. But the Lebanese TV station al-Mayadeen earlier reported he had
been killed in an Israeli attack. Israel has not responded to the claims.