Shi'ite Muslim militant group Hezbollah, whose top commander Mustafa Badreddine was killed in Syria this week, said Sunni insurgents were responsible for the explosion near the Damascus airport which left him dead. Earlier reports on Friday had suggested an Israeli airstrike had killed Badreddine, but the claims were later withdrawn. 

Hezbollah said on Friday that Badreddine had been killed in Syria, where he was overseeing the group's military operations  in support of Syrian President Bashar al-Assad against Sunni Muslim groups, including the Islamic State group and the al Qaeda-affiliated Nusra Front. 

"An investigation has shown that the blast that targeted one of our positions near the Damascus international airport that led to the martyrdom of the brother commander Mustafa Badreddine was caused by artillery bombardment carried out by takfiri (Sunni extremist) groups present in that region," a Hezbollah statement said, according to AFP. Hezbollah, however, did not name any particular group for Badreddine's death. 

Baddredine was allegedly involved in the assassination of Lebanon's former prime minister Rafik al-Hariri in 2005 as well as the 1983 bomb attacks in Kuwait, for which he was given the death sentence.

Baddredine's funeral was carried out in Beirut in Lebanon in the presence of hundreds of mourners. He was the senior-most Hezbollah member to have been killed since the assassination of his brother-in-law Imad Mughniyeh in a joint Mossad-CIA operation in Damascus in 2008.

"The outcome of the investigation (into Badreddine's death) will increase our determination ... to continue the fight against these criminal gangs and defeat them," Hezbollah said on Saturday.