The embargo, agreed last week by EU ambassadors and formalised on Monday by EU foreign ministers, `is in place', the spokesman said.

The sanction forbids EU citizens and companies providing oil and oil-related services to Yugoslavia, with only two exceptions: supplies of oil for humanitarian needs -- in particular for refugees fleeing Kosovo -- and oil deliveries already on their way before the ban comes into effect.

NATO, at the same time, blitzed Belgrade early today, leaving dead and injured, in one of the heaviest raids yet in the five-week-old bombing campaign against Yugoslavia.

But radio reports said NATO missiles hit civilian area as well as the headquarters of the Yugoslav army general staff and the federal police, destroying houses and injuring a man and his pregnant wife.

The area wascordoned off by police and teams of firemen and ambulances rushed to the scene but no fire was visible from the street.

The blast blew out the windscreen of a fire service vehicle which was driving past at the moment of the explosion, according to one of the firemen riding in it. The fireman, who suffered minor head injuries, was taken away in an ambulance.

According to witnesses questioned at the scene, several other buildings in the same neighbourhood were hit and there were several casualties.

The government offices and those of the yugoslav foreign ministry lie opposite the army HQ.

Radio Novosti, quoting unofficial sources, said at least two NATO missiles fell on two groups of small houses about three kms southeast of the city centre.

In one house, which was razed to the ground, Djordje Djuric, 28, and his pregnant wife Dragna were dragged from under the ruins by neighbours and taken to hospital.

A second house, including the Zlanti Ovan cafe, was obliterated, radio correspondent VladimirKrasic said.

Water mains were damaged, and water was running through the streets.

According to residents of the area, contacted by telephone earlier, at least two houses had `vanished' after the explosions which left two `huge craters' where the houses used to stand.