The Nato supreme commander, Gen Wesley Clark, yesterday called for acceleration of the deployment of alliance peacekeeping troops in Kosovo and said the mission might need more soldiers than first planned.
In the 12 days since the first units entered Kosovo the alliance has deployed just over 17,000 troops in the province, roughly one-third of a total of 55,000 earmarked for the job.
Senior NATO military officials said that had been a fair start, but it was not enough.
"I am calling on NATO governments to accelerate the arrival of the troops to the greatest possible extent," Gen Clark said in a telephone interview from his headquarters in Mons, Belgium.
Gen Clark also said there was "room for more" than 55,000, but the main thing was to get the resources already promised into Kosovo without delay.
"There are not enough troops in there now," he said.
Kosovo is a relatively small territory of 4,300 square miles. But NATO troops are for the moment the only strong, independent authority people can turn to.
In many of the remoter parts of Kosovo, particularly some western and central regions, villagers have yet to meet any of the NATO peacekeepers, whose presence has brought immediate reassurance if not an end to uncertainty in the main towns.
The proliferation of arms, the presence of mines and unexploded NATO ordnance, the fear of reprisal attacks and the flight of terrified Serb civilians leaving homes ablaze are all keeping tensions high.
Revenge shootings have become an almost daily occurrence in the capital, Pristina, and Pec, a partly looted and burnt city in the west. Even with the formal disarmament of the KLA now under way, the province will remain awash with firearms.
A senior NATO official said there was a major difference between Kosovo and Bosnia, a country three times its size, where 60,000 troops were deployed for the initial peace implementation phase of a political settlement.
"In Kosovo, a fundamental difference is that there is no peace agreement as there was in Bosnia," the official said.
The Serb-dominated civil administration has collapsed, the police are gone, and nothing has been installed to replace them apart from the NATO peacekeeping force, which is being stretched in all directions.
People who find the murdered bodies of relatives, whose homes have been burned or who are threatened or at risk have no one to turn to but the KLA or the nearest NATO soldier.
The guerrilla force had an understandable desire to be seen as a recognised and legitimate force, the official said.
In remote parts of Kosovo, its black-uniformed military police are now the only law, and its soldiers guard factories and other valuable installations. They are trusted by Kosovo Albanians and it would be counterproductive to remove them from the scene before NATO is able to take over the responsibilities.
Disarming the KLA was now a high priority goal for NATO but, "as always in the Balkans, long experience of violence makes people wary" of giving up their guns, the official said.
Some elements would try to resist the agreement, the official said. It was also highly probable that Serb paramilitary gunmen were lingering on in Kosovo after the departure of uniformed forces, or filtering back.
On Monday two British soldiers, two others and a fifth person were killed when unexploded NATO cluster bomblets gathered for disposal blew up.
Gen Clark said more NATO army engineers and munitions clearance specialists were on their way to Kosovo and arrangements were being made for United Nations police, with sidearms, to help maintain law and order.
It was clear that NATO would have been better off with all its Kfor mission ready to enter Kosovo at once, but there had been enough to secure the timely withdrawal of Yugoslav forces and to get a grip on the situation, the official said.
NATO knew there was a risk of revenge attacks, he added. Such violence was not going to be any less of a risk even after UN police were deployed.
Deborah Charles reports from Belgrade:
Hundreds of ethnic Serb refugees who fled Kosovo in fear of their lives headed back to the province yesterday, but Serbian officials said some were going to camps, not their homes.
On the third day of a government-organised effort to send Kosovo Serbs back to the province, hundreds boarded buses or loaded their cars and tractors with free fuel and headed south.
Government officials who accompanied the refugees said some of them would be housed in camps in two towns in northern Kosovo until it was safe to return to their homes.