The man believed to be Hezbollah's most senior military commander in Syria's war has been killed in Damascus.

Mustafa Amine Badreddine died in a large explosion near Damascus airport, the Lebanon-based militant group said in a statement on its al-Manar website.

Hezbollah supports Syria's President Bashar al-Assad and has sent thousands of fighters into Syria.

In 2015, the US said that Badreddine was behind all Hezbollah's military operations in Syria since 2011.

The US treasury, which imposed sanctions on Badreddine last July, said at the time he was behind the movement of Hezbollah fighters from Lebanon to Syria, and was in charge of the key battle for the town of al-Qusair in 2013.

Badreddine was also charged with leading the assassination of former Lebanese PM Rafik Hariri in Beirut in 2005.

The funeral for Badreddine is scheduled for Friday afternoon south of the Lebanese capital, Beirut.

Death near Aleppo?

An initial report by Lebanon's al-Mayadeen TV said that Badreddine, 55, died in an Israeli air strike. But a later statement by Hezbollah on al-Manar's website did not mention Israel.

Israeli media reported that the government refused to comment on whether it was involved in Badreddine's death.

Israel has been accused by Hezbollah of killing a number of its fighters in Syria since the conflict began.

The group was established in the wake of the Israeli occupation of Lebanon in the early 1980s, and has called for the "obliteration" of Israel.

A number of Twitter accounts supporting Syrian rebel groups and the al-Qaeda-affiliated al-Nusra Front say Badreddine was killed in a battle in Khan Touman, southern Aleppo, rather than in Damascus.

Khan Touman was captured by a coalition of groups including al-Nusra Front last week and has been subject to heavy shelling in recent days.

No official sources have commented on the reports.

Born in 1961, Badreddine is believed to have been a senior figure in Hezbollah's military wing. He was a cousin and brother-in-law of Imad Mughniyeh, who was the military wing's chief until his assassination by car bomb in Damascus in 2008.

According to one report, a Hezbollah member interrogated by the Canadian Security Intelligence Service (CSIS), described Badreddine as "more dangerous" than Mughniyeh, who was "his teacher in terrorism".

They are alleged to have worked together on the October 1983 bombing of the US Marine Corps barracks in Beirut that killed 241 personnel.

Badreddine is reported to have sat on Hezbollah's Shura Council and served as an adviser to the group's overall leader Hassan Nasrallah.

A number of Twitter accounts supporting Syrian rebel groups and the al-Qaeda-affiliated al-Nusra Front say Badreddine was killed in a battle in Khan Touman, southern Aleppo, rather than in Damascus.

Khan Touman was captured by a coalition of groups including al-Nusra Front last week and has been subject to heavy shelling in recent days.

No official sources have commented on the reports.

Born in 1961, Badreddine is believed to have been a senior figure in Hezbollah's military wing. He was a cousin and brother-in-law of Imad Mughniyeh, who was the military wing's chief until his assassination by car bomb in Damascus in 2008.

According to one report, a Hezbollah member interrogated by the Canadian Security Intelligence Service (CSIS), described Badreddine as "more dangerous" than Mughniyeh, who was "his teacher in terrorism".

They are alleged to have worked together on the October 1983 bombing of the US Marine Corps barracks in Beirut that killed 241 personnel.

Badreddine is reported to have sat on Hezbollah's Shura Council and served as an adviser to the group's overall leader Hassan Nasrallah.