In the villages of central Kosovo, bordering the wooded hill-sides of the Glogovac region, we have been asking questions for 10 straight hours.

Mine-clearance takes expertise in explosive ordinance disposal - but it also requires the dogged persistence of a policeman.

It is becoming clear that, in this area, there has been widespread and indiscriminate laying of mines by Serb forces - mines intended to injure people returning to their homes.

A deadly discovery in a Kosovo garden

Halo teams are de-mining in countries as far apart as Angola and Abkhazia, Cambodia and Afghanistan.

We have been contracted by the UK Government to conduct a nationwide survey of the mine problem in Kosovo.

We have come up a steep gully to a small hamlet with red-clay tile roofs.

The villagers here have only been back in their homes for two days, and the people's faces have a pinched, hollowed-out look from living rough in the Cicativa mountains.

Halo Trust: Clearing up after wars around the world

Our Kosovo team has been pulled in from mine-clearing duties elsewhere. Last week, I was with Halo's operation in Cambodia.

We arrived in the province with the leading elements of the British army, but K-For patrols have not pushed this far yet: we are the first "liberators" the villagers have seen.

People emerge from the burned shells of their houses - old men in felt pillbox hats clap their arms around us.

Intelligence shared with K-For

They show us the farm buildings used by the Serb militia as a base.

North of the building, cattle have been injured by anti-personnel mines. In the steep valley to the east we find two PMA3s and a PMA2 - mines made in the munitions factories of the former Yugoslavia.

We establish a reference point, record its grid reference. I take digital photos while my colleague, Mark Frankish, sketches the mine-field.

The information will be fed into the Halo database and made available to K-For, as well as other humanitarian organisations working in the area, and the fledgling Kosovo Mine Action Centre.

Mine-clearance is a methodical, time-consuming process.

It is vital to build up a picture of the extent of the problem, so that clearance tasks can be prioritised, the worst areas targeted first.

Accidents help locate mine-fields

Then we move on to the next village, and more questions.

We find an ambush site, where Adem Advuli - returning to a wooded copse where he had hidden his tractor from the Serb police - stepped on a mine, losing his leg.

His uncle, Nazmi, spotted another mine, and threw stones at it until it exploded.

Refugees have flooded back into Kosovo despite land-mine warnings

Suggesting to him that this is not a sensible course of action, we record the details of the mine-field.

Many returning refugees have, sadly, triggered land-mines.

It is an uncomfortable truth that in the absence of clearly-marked mine-field maps, accidents provide the earliest intelligence.

Unpleasant discoveries

Investigating what was a Yugoslav army position close to the village of St Cikatovo, we uncover a mass grave.

The corpses of men, women and children have been dumped in trenches and hastily covered. Body parts are visible.

Behind the trenches, we find fragmentation mines initiated by trip-wire: a trap for anyone investigating the graves.

A role for the KLA ?

While we are still investigating, soldiers from the Kosovo Liberation Army (KLA) appear and disarm the mines.

But we are concerned that they may not have cleared them all.

We have heard reports of villagers returning to homes "cleared" by the KLA and setting off missed mines.

The KLA, however, are enthusiastic about sharing information with us.

Given the right training and management, these soon-to-be demilitarised guerrillas could form the nucleus of an indigenous mine-clearance capacity.

Our next task is to check the premises of the Kosovo Albanian national newspaper, Koha Ditore, for booby-traps.

Then it's on to the British Embassy.