He was inside a third-floor apartment which had an explosive device strapped to its door.

The blast blew off a metal security door and the wooden front door of the flat.

Three Albanian children from neighbouring flats were also taken to hospital with light injuries.

The man, believed to be in his 60s, was the only Serb still living in the block.

The explosion happened at around 2230 local time, a spokesman from the Royal Irish Regiment said.

He said the device was around 2kg in size and consisted of high explosive.

The incident is the latest and most serious in a series of attacks against Serbs in the province.

There has been widespread intimidation in the past weeks of the 1,000-2,000 remaining Serbs in the capital.

Many hardly dare leave their homes for fear of attack.

Friday night's bomb seems designed to drive out those who are still trying to stay.

Ten kilometres outside Pristina, in the town of Gracanica, local Serbs have been blocking the road since Wednesday in protest against a series of kidnappings.

They are demanding more action from the UN mission in Kosovo to protect their communities and find those responsible for the violence.

Their leaders allege that these are not isolated acts of revenge but part of an orchestrated campaign to drive all Serbs out of the province.