Serbs Begin a Pullback at Gorazde : Bosnia: U.N. troops patrol the enclave as gunmen who had battered the city retreat in the face of a NATO ultimatum. The rebels blow up a water plant on their way out.

U.N. troops arrived in shattered Gorazde on Sunday to patrol the Muslim enclave after Bosnian Serb rebels made a grudging retreat, leaving a trail of destruction in their wake.

As they withdrew their weapons from the so-called “safe haven,” the Serbian gunmen torched overrun villages and blew up the water plant on which the enclave’s 65,000 residents depend.

Officials of the U.N. Protection Force gave contradictory reports on the degree of Serbian compliance with a NATO order that the rebels retreat 1.9 miles from the center of town and cease the assault that inflicted 3,000 casualties in little more than three weeks.

One U.N. aide said Serbian infantrymen were trying to hold at least two positions within the exclusion zone and that fighting continued around such key facilities as the Pobjeda munitions works.

The commander of the U.N. forces in Bosnia, Lt. Gen. Michael Rose, said that there were too few U.N. troops in Gorazde to verify full compliance with the North Atlantic Treaty Organization order.

Rose also confirmed that the rebels blew up the city water plant Sunday, and that some heavy artillery fire continued well after the 2:01 a.m. deadline for retreat.

Like U.N. special representative Yasushi Akashi, the civilian chief at mission headquarters in Zagreb, Croatia, Rose has sought to prevent the peacekeeping force from being dragged militarily into the Balkans conflict.

“We do not have to bomb our way to peace,” Rose said in resisting NATO calls for attacks on Serbian positions.

Officials of some NATO countries, however, have concluded that evenhandedness is getting nowhere with the Serbs, who have conquered 70% of Bosnia in a war that has left 200,000 dead or missing and nearly half the population displaced.

And the fierce Serbian artillery assault on Gorazde was, for many political leaders, too savage and calculated to be ignored. Most of the dead and wounded were women, children and men too old to fight.

NATO’s ultimatum, issued Friday, demanded an immediate cease-fire, the troop and artillery pullback and unimpeded access for U.N. and humanitarian operations.

The Serbian forces have violated all the conditions. But Akashi has refused to authorize punitive air strikes, instead renegotiating some terms of the ultimatum with Serbian rebel leaders and their patrons in Belgrade.

The NATO call for freedom of movement for U.N. and aid workers was redefined to be “normal conditions,” one aide to Rose disclosed. The Serbs interpret that to mean they can demand prior clearances for each vehicle and person passing through rebel-held territory.

The first medical evacuations from Gorazde were delayed at least two hours when Bosnian Serb leader Radovan Karadzic ordered the U.N. helicopters transporting patients to Sarajevo to stop in the Serb-held town of Sokolac so his gunmen could inspect them.

No patients were detained, but an official with the Office of the U.N. High Commissioner for Refugees and a pool of foreign journalists were scratched from the flight lists at the Serbs’ insistence.

The Serbs also delayed the arrival of a U.N. convoy of food and medical supplies--critical humanitarian aid that the Serbs had denied the city’s desperate residents for months.

The aid convoy--14 Russian trucks carrying 89 tons of wheat flour, food parcels, medicine and other supplies--arrived in Gorazde late Sunday night after being blocked for much of the day at a checkpoint on the border between Serbia and Serb-controlled Bosnian territory.

The Serbs said they held up the convoy because they did not have authorization to let it pass from Bosnian Serb authorities, even though the rebels’ leadership had pledged to U.N. officials that the trucks would be allowed through. Another 10-truck convoy is expected to leave Belgrade for Gorazde today.

“The ultimatum is dead, completely and absolutely,” one disillusioned aid official declared as he waited for the wounded to arrive.

Those evacuated described Gorazde as relatively calm after day-break Sunday, with small-arms and sniper fire continuing but a marked drop in the number of mortar and artillery rounds.

Rose painted a considerably less dire picture of the scene in Gorazde, as relayed to him by U.N. officers inspecting cease-fire lines.

“The citizens of Gorazde are out walking in the streets for the first time in three weeks,” Rose told reporters. “It’s obviously an enormous relief for them that (U.N. troops) have arrived, giving them some assurance that the NATO ultimatum is being complied with.”

The British general indicated that aerial reconnaissance photos show the Serbs packing up and moving out toward the 12-mile perimeter of the weapons exclusion zone proclaimed around Gorazde.

NATO gave the Serbs until early Wednesday to pull out all heavy weapons from that zone or risk provoking air strikes.

Rose said the movement of heavy weaponry would be closely monitored and additional steps taken as necessary to prevent new attacks on Gorazde, which was targeted after NATO threats forced the Serbs to move their artillery away from Sarajevo in February.

“I don’t say we trust them at all after what has happened,” Rose said of the Serbs, speaking to reporters outside his sandbagged residence.

Rose described the Gorazde offensive as “a disastrous strategic error” that inflicted a humanitarian crisis for little tactical gain, and said he hoped the rebels had decided to “abandon this warmongering policy and head down the path of peace.”

Bosnian government supporters, however, worry that NATO’s failure to use force against the Serbs besieging Gorazde will simply encourage the rebels to press their campaign for territory in some area of Bosnia-Herzegovina where the United Nations is less vigilant.

There was also concern that the U.N. troops deployed to Gorazde would in effect provide a human shield for the Serbs, further deterring air strikes.