A self-proclaimed commander of Albanians fighting with Islamic State in Syria and Iraq, notorious at home in Kosovo for a video showing him beheading a man, has been killed, police and his family said on Thursday.

Lavdrim Muhaxheri died in the Middle East, but it was not clear in which country or when, they told Reuters.

A video posted on the Internet in 2014 showed Muhaxheri beheading a young man in Iraq accused by IS of spying for the Iraqi government. Another video showed him killing another person with a rocket-propelled grenade.

A police official, who declined to be named, told Reuters that he had been killed, but gave no other details.

Confirming his death, an uncle of Muhaxheri asked a Reuters reporter: "Is everyone happy now?"

Around 300 Kosovars have gone to fight with Islamic State and more than 50 have been killed, Kosovo officials say.

About 120 more are estimated to have left from Albania itself and about 100 from Macedonia's Albanian minority.

Kosovo has not seen any militant attacks on its home turf, but at least 200 people have been detained or investigated for alleged Islamic State-related offences

Most of Kosovo's ethnic Albanian majority are nominally Muslim but overwhelmingly secular. Kosovo declared independence from Serbia in 2008 with the backing of the West.

In 2015, it adopted a law introducing jail sentences of up to 15 years for anyone found guilty of fighting in wars abroad.