BUKOS, Yugoslavia, June 21 (AFP) - UN humanitarian relief operations in Kosovo kicked up a gear Monday, with aid agencies sending out helicopters carrying emergency food rations for hungry Kosovars cautiously returning to their villages.

Two big white helicopters chartered by the World Food Programme (WFP) were in their second day of shuttling out the rations to remote communities in areas hard hit by months of conflict, a WFP spokeswoman, Christiane Berthiaume, said.

The main reason for using the aircraft was the problem of landmines, she said.

Some of the villages may look easily accessible, but the narrow roads, many of them still bearing the marks of Serb army tank tracks, were considered high-risk for the hidden weapons.

Bethiaume was speaking inside one of the helicopters as it came to land in this village in hills northwest of the provincial capital Pristina.

Outside, a group of around 30 excited villagers pressed forward as boxes of high-protein rations were handed out.

Men, women and children, some of them obviously underfed after spending weeks living in a nearby forest, were seen dragging the boxes off into the grass and picking at the packing tape sealing them.

"We're flying out about 1,000 rations per flight" and sending out a total of about four flights a day, Berthiaume said, adding: "It's not only food we're bringing, but hope."

As she spoke, two workers with the humanitarian organisation World Vision -- one of several bodies working with WFP -- who had been dropped in the village earlier in the day to prepare for the food handout boarded the helicopter.

One of them, Anne Henderson, said those lining up for the boxes represented only about 20 percent of the local inhabitants, many of whom had spent "two months in the mountains, with no food for the last few weeks but some flour and salt."

The men were worst off, while the children had fared best because of the adults sacrificing their own needs for their offspring, she said.

"But all of them were covered in scabies" because of their inability to wash for so long, and clean drinking water was a real problem, she said.

Henderson added that the danger of mines was very real. "We saw three different tripwires. We marked them, and told them (the locals) not to touch them," she said.

Back at the helicopters' landing field just outside Pristina, another WFP official, Abby Spring, said "safety was a very big concern... If you can't get to the people, you can't feed them."

She admitted that the technique of flying in rations was "hit and miss" at the moment, but that it was faster than setting up distribution by road and it allowed the WFP to quickly form a picture of the regions in greatest need.

The helicopter flights were also delivering a valuable message to the communities, she said, which was: "Stay in your villages, food is on the way."

Spring said the WFP had enough food stockpiled in the region to feed 1.5 million people -- roughly those estimated to have taken refuge in neighbouring states plus the number of internally displaced -- for 45 days.

But, she warned, the food assistance programme was no short-term affair. After the initial emergency phase with the helicopters, truck deliveries were going to take over -- and continue well into next year.