U.N. Warns That Bosnia’s War Could Spill Over Into Croatia Plane Violates ‘No-Fly’ Zone; Rival Troops Mass In ‘Safe Area’

A mysterious cargo plane delivered supplies to embattled government troops in the northwest enclave of Bihac, where rival forces massed Thursday amid U.N. warnings that Bosnia’s war could spill over the nearby border into Croatia.

A NATO surveillance plane over the Adriatic Sea picked up radar “tracks” that showed the plane approaching and returning from an airfield in Coralici, in the northern part of the Bihac enclave, in violation of the U.N. “no-fly” zone over Bosnia. The airplane landed Wednesday night and took off at 1 a.m. Thursday, said U.N. spokesman Chris Gunness.

Rebel Serbs shelled the area soon afterward, but NATO war jets patrolling the no-fly zone took no action. The plane apparently slipped in quickly from Croatia, which is just six miles to the north and not included in the military flight ban.

NATO jets would not have waited overhead for the plane to take off again because of the threat of Serb surface-to-air missiles in the area.

U.N. officials said approximately 2,000 Croatian troops have been deployed north of the Bihac enclave in the last several days. Attacking rebel Serbs now control about one-third of Bihac, which is home to 200,000 people.

Bihac, one of six U.N.-declared “safe areas,” has drawn both rebels and government forces from nearby Croatia and threatens to reignite the conflict simmering in Croatia since a January 1992 truce ended a six-month war there.

On Saturday, the leaders of Bosnia and Croatia agreed to increase military cooperation, specifically to protect Bihac. The agreement also gave Croatia the green light to launch other attacks from within Bosnia.

About 500 Croatian government troops crossed the border into southwestern Bosnia and were advancing on a supply route linking Serb rebels in Bosnia with those in Croatia, said U.N. spokesman Rida Ettarashany. All told, about 2,500 Croatian troops were in southwestern Bosnia, Ettarashany said.

Alarmed U.N. officials announced plans to reinforce peacekeepers separating Croatian government and rebel troops in Croatia as well as along the Croatian-Bosnian border.

But they still had to rely on the good will of the warring sides to station the additional troops because both Croats and Serbs have blocked peacekeepers from combat zones. If blocked, peacekeepers would “apply passive resistance,” said Col. Norris Pettis, chief of staff for the U.N. command in Croatia.

“We’ll be stubborn,” he explained.

He said the decision was not “directly in response to Bihac, although I’m concerned that the events are overtaking this plan and it already may be too late.”

The mysterious cargo plane was the first large fixed-wing aircraft known to have landed in the Bihac enclave.

Capt. Jim Mitchell, a NATO spokesman, said that NATO is investigating what the plane was carrying and where it was headed after leaving Bihac.

“It brought supplies for the Bosnian army,” said Col. Jasper Helsoe, U.N. commander in Bihac. “We don’t know what was inside it.”