ASSOCIATED PRESS WRITER

GEORGE JAHN

SARAJEVO, Bosnia-Herzegovina (AP)—Croat forces unleashed at least four separate attacks against Muslim areas of Bosnia on Thursday in apparent retaliation for the massacre of Croat civilians.

Croat forces bombarded Muslim parts of Mostar and Vitez, and the Muslim-held towns of Gornji Vakuf and Jablanica. U.N. officials, reporting the attacks, did not have casualty figures.

The United Nations issued an unusually direct and detailed statement condemning Muslim-led government troops for the massacre, which it called a ‘‘cowardly atrocity.’‘

The killings took place Tuesday in Kriz, near the village of Uzdol in central Bosnia. Lt. Col. Bill Aikman, a spokesman for U.N. peacekeepers, said a British commander reported seeing at least 35 bodies, mostly of elderly people and including one young girl.

The U.N. statement said 70 to 100 Bosnian government soldiers launched an early morning attack on the hamlet, luring out Croat villagers. Government forces then crept around the Croat positions and attacked the Croat command in the village, killing two Croat soldiers, it said.

‘‘This group then retreated, murdering the remaining population with firearms, knives and axes, and setting fire to some houses,’‘ it said.

The United Nation’s Bosnian command will investigate the slayings, the statement said. Cedric Thornberry, the most senior U.N. civilian in the region, demanded ‘‘speedy and exemplary punishment’‘ for the perpetrators.

Meanwhile Thursday, mediators in Geneva asked Bosnia’s Serb, Croat and Muslim leaders to meet in Sarajevo next week to sign a peace settlement.

‘‘We believe big steps toward peace will be taken in the next few days,’‘ said international mediator Lord Owen, who was visiting Turkey.

The announcement was part of a Serb-Muslim accord in which Bosnian President Alija Izetbegovic, a Muslim, agreed in the clearest terms yet to possible secession by Bosnian Serbs and Croats to join neighboring Serbia and Croatia.

The agreement calls for a cease-fire by Saturday at the latest, releases of prisoners and open routes for aid convoys. A similar cease-fire agreement was signed Tuesday between Izetbegovic and Croatian leaders.

An earlier full peace package fell apart Sept. 1 before being signed, when Croatian President Franjo Tudjman refused Izetbegovic’s demand for access to the sea at the Adriatic port of Neum and the Bosnian Serbs balked at ceding any more territory.

A weary Izetbegovic, meeting with reporters in Sarajevo after returning from Geneva, insisted, ‘‘We will not give up our requests.’‘

The Serbs hold about 70 percent of Bosnia-Herzegovina and the Croats most of the rest after nearly 18 months of civil war.

The fighting, which began when Bosnian Serbs rebelled against a vote by the Muslim-Croat majority to secede from Serb-dominated Yugoslavia, has left as many as 200,000 people dead or missing and made refugees of 2 million.

Bosnian Croats and Muslims, initially allies against the Serbs, have been fighting for months in increasingly bitter attempts to grab as much territory as possible before a peace settlement.

Lt. Gen. Francis Briquemont, commander of U.N. forces in Sarajevo, said he would meet commanders of both sides Friday to start implementing the agreement between Bosnia’s Muslims and Croats.

Also Thursday, Bosnian Serb leader Radovan Karadzic sought in vain to end a rebellion by elite troops in the northern Bosnian town of Banja Luka against alleged war profiteers.

In Croatia, Croatian forces withdrew from three Serb villages whose capture had threatened to ignite Serb-Croat hostilites, the Croatian Serb army said in a statement. The U.N. said peacekeepers moved in.

But Belgrade TV later reported a Croatian attack on Knin, center of the Serb minority rebellion in Croatia.

A reporter for Knin radio, Petar Topovic, told The Associated Press in Belgrade by telephone that 25 shells landed, several hitting downtown Knin.

There was no word on casualties.