In the inviting waters of the Adriatic, the unglamorous workhorse of the Royal Navy has landed the job of cleaning up after Nato.

Two hundred and thirty five bombs were jettisoned here during the Kosovo conflict. The minsweeper HMS Atherstone is part of a force tasked to find and destroy them.

It is a frustratingly slow business - six weeks to find 10 bombs. Round the clock shifts, as the team in the operations room - the "gloom room" - watch the orange readout from the sonar inching across the seabed. Sadly there is no satisfying "ping" from it any more. That might set off sound activated mines.

When contact is finally made it is time to bring in the ship's pride and joy. A yellow mini-submarine, with a hint of James Bond about it, is launched.

Its television pictures relayed back to the ship soon confirm this is not one of the many rusty refrigators or sunken barrels that seem to line the ocean floor. This is the genuine article: a 500lb general purpose bomb that never made it to Yugoslavia.

HMS Sandown has also joined the hunt

After an explosive charge is laid, the Atherstone retreats to a safe distance. Surrounding shipping is warned to steer clear.

A high pitched subterranean beep detonates an explosion 70 metres below the surface. The shock waves ripple to the surface.

"Loud bang heard" reports the rating drily back to the bridge. Loud bang equals one less bomb to snag the fishermens' nets.

Bombers have been using the Adriatic as a dumping ground since World War I. Sometimes it is just not safe to landed with bombs still on board.

But two months ago Italian fishermen caught one in their nets. It exploded, injuring three men.

Nato, among its many apparent blunders, had failed to advertise the hazard. There was outrage in Italy, so this unprecedented clean up operation was promised.

The fishermen are still not satisfied. In the port of Ancona, and up and down the east coast of Italy, the fishing fleets have not moved from the quayside for two months.

We met a fisherman called Raptis Michele, cleaning his boat, and trying to earn extra money helping some of the few inshore fishermen still operating.

Civilians were killed and injured when this bridge was hit

He reckons he has lost hundreds of pounds because of the stoppage. And he says he will not believe it even if the government says it is safe again.

Of course, as many locals believe, the fishermen could be playing this one up to milk more money out of the government. But the episode of the bombs has not endeared Nato to a country which only reluctantly found itself on the front line of the war in Yugoslavia.

On board the Atherstone, the Captain, Lt Cmdr Mark Durkin, is confident of success in this endeavour, strangely named Operation Allied Harvest.

"We're in ideal conditions here," he insisted. "The weather is very good, the sea condtions are very good, and with the equipment that we have we're getting a very large amount of coverage of this area."

World changing

"We're taking our time, there's no rush and the whole aim is to give as high a degree of confidence as we can to the Italian fishermen and the local people that we have cleared this area."

It is not all as easy as finding a 500lb lump of metal. Some cluster bombs have sprayed hundreds of little bomblets across the sea floor. So the sea bottom is never going to be made entirely safe.