ON Sunday, a French UN peacekeeper was wounded, a French armored personnel carrier was destroyed by a Bosnian Serb tank, and seven Bosnian civilians were killed by a Bosnian Serb shell as they waited in a school to collect drinking water.
At the same time, four captured Bosnian Serb soldiers, participants in a gun battle that left four French soldiers dead, were exchanged for the remaining 26 United Nations hostages held by the Bosnian Serbs - hostages UN officials said they would never negotiate for when they were seized last month.
When asked to explain the exchange on Sunday, the new top civilian UN official in Bosnia, Phil Corwin, said he didn't know.
"The decision was made at higher levels," Mr. Corwin says. "Somebody else did it. It wasn't my deal."
Corwin's answer reflects the growing disarray of a UN mission being increasingly tested by both sides in the conflict.
Officials at UN headquarters in Zagreb, Croatia, are holding public and secret meetings with the Bosnian Serbs, while military officials in Sarajevo are preparing for possible conflict with authorities they deride as "hostage-takers."
Weeks of indecision on the UN Security Council in New York is leading to confusion on the ground in Bosnia and risking peacekeepers' lives, according to critics here. And the new Serb shelling attack led the Bosnian government to again call for the UN to act decisively or lift its arms embargo over the former Yugoslavia.
Another example of UN disarray occurred on Sunday. Corwin met with Bosnian Serb leaders in their headquarters in Pale to discuss having the Serbs restore electrical, gas, and water supplies to Sarajevo - cut off three weeks ago. During the meeting, he did not protest the shelling or bring up the critical food situation in Sarajevo.
"I wasn't authorized to negotiate on other issues," Corwin said in a testy exchange with reporters who questioned why he didn't raise the shelling attack.
"There is no logic in your question," Corwin said, "I don't feel the need to respond to it."
At the same time Corwin was meeting with Serbs, UN military officials were preparing for future possible conflict.
Nearly all remaining UN peacekeepers were quietly withdrawn from Bosnian Serb territory Sunday to prevent them from being used as hostages in the future.
The peacekeepers abandoned a handful of remaining UN weapons-collection points around the city, and UN military officials admitted that the 12.5 mile heavy-weapons exclusion zone established around the city after a Serb shell killed 68 civilians last winter no longer exists.
With the collapse of the heavy-weapons exclusion zone, shelling is expected to intensify in Sarajevo. Sunday's water-line attack was the worst on a purely civilian target since the February 1994 marketplace massacre and resulted in images of civilian victims flashing across television screens worldwide.
But UN officials here say the removal of the potential UN hostages has created an opportunity for the UN to carry out its mission of delivering humanitarian aid with or without the cooperation of the Serbs.
"We have secured our personnel," UN military spokesman Lt. Col. Gary Coward said yesterday. "It does give us an opportunity to establish a new relationship with the Bosnian Serbs."
With the redeployment of peacekeepers, the arrival of elements of the new 10,000-troop-strong UN Rapid Reaction Force, and UN personnel in Sarajevo set to run out of food and fuel supplies at the end of the month, the ground has been laid for a "watershed" according to Colonel Coward.
A plan suggested by the UN commander in Bosnia, British Lt. Gen. Rupert Smith, to open a UN-secured humanitarian aid route into Sarajevo over nearby Mt. Igman could be enacted. UN officials say their own food shortage, unlike ongoing civilian food shortages, may force their hand.
"If we run out of supplies," says a UN official. "We'll be forced to take action."
UN officials, who have been told to take no offensive military action until they receive guidance from the Security Council, expect more UN disarray, more civilian deaths, and more Serb provocations.
The Bosnian government, frustrated with the UN's indecisiveness, is pressing on with a slow-moving offensive designed to stretch Serb forces out across Bosnia and relieve the Serb siege of Sarajevo.
But the UN announced yesterday that a key supply route between Sarajevo and Serb headquarters in Pale believed to have been cut by government forces had been retaken by the Serbs.
Bowing to Western pressure, Bosnian President Alija Izetbegovic made a token peace offer Sunday night. In a presidential statement, Mr. Izetbegovic said the offensive would be halted if the Serbs agreed to the removal of all heavy weapons from the exclusion zone, restored gas, electrical and water supplies to the city, and allowed the Sarajevo airport and ground routes to open for humanitarian shipments.
The Serbs are unlikely to accept the offer, and while the UN waits for its supplies to run out, the humanitarian situation in Sarajevo worsens.
UN food warehouses are empty, and food convoys scheduled to enter the city in the next few days may be canceled because of continued fighting.
"In our last food distribution [two weeks ago] we were able to meet only 15 percent of our target," UN High Commissioner for Refugees spokesman Mark Cutts said yesterday.
"Our next food distribution is to begin in two days. Unless we get food into the city, we will be able to deliver zero," Mr. Cutts added.