Islamic State (Isis)'s finance chief has been killed by an air strike carried out by the US-led coalition in Iraq and Syria, according to a US military spokesman.

Army Colonel Steve Warren said Abu Salah was killed along with a senior leader responsible for coordinating the group's extortion activities and another leader who acted as an executive officer.

He told a Pentagon briefing that Abu Salah, whose real name is Mohammed al Karmoush, was one of IS (Daesh)'s most senior and experienced members:

The aerial bombings against IS's leadership network "will degrade Isil [another name for Daesh]'s ability to command and control troops and it disrupts their ability to finance their efforts," Brett McGurk, the US government's envoy for the fight against IS, said.

The US-led coalition is also involved in raids against IS in Ramadi, Anbar provincial capital, which has become the focus of a massive campaign by Iraqi forces. The Pentagon said air strikes over the city killed 350 IS fighters in the past week

Ramadi, situated about 120km from the Iraqi capital Baghdad, was captured by IS in May following a spectacular retreat by Iraqi forces. Iraqi government forces have wrestled back a large area on the south-western side of the city and are closing in on the jihadists holed up there.