By Patricia Gossman

It is hard to imagine that life could get any worse for the people of Afghanistan. But in the past few weeks civilians in the central highlands have been caught in a cruel game as back-and-forth fighting between the governing Taleban and the opposition United Front alliance has raged through the region. Recently at least 170 civilians in the town of Yakaolang were forced from their homes and executed by Taleban troops. Those killed belonged to the Hazara minority, Shiite Muslims whom the Taleban tend to regard as non-Muslims and persecute accordingly.

The UN Security Council recently increased sanctions on the Taleban to pressure them to hand over Osama bin Laden, who is wanted by the United States for alleged involvement in terrorism. But there is more to Afghanistan than Mr. bin Laden, and mass killings of civilians deserve attention.

Human Rights Watch and other international monitors have counted 12 massacres of noncombatants by various factions in four years. In not one of these cases has there been any effort by the international community to indict those responsible, even though some of the commanders believed to be in charge continue to travel in Europe, the United States and Central Asia.

The Security Council and influential donor countries should support a prompt UN or international inquiry into the massacres and post observers on the ground. The evidence gathered should be used to ensure that those responsible are punished.

There is little hope that the Taleban will prosecute their own commanders. The movements of commanders identified in an international investigation as having supervised the killings should be monitored, and they should be arrested if they leave Afghanistan.

Most of Afghanistan's neighbors continue to send covert military assistance to clients inside the country. The arms provided have been used in serious violations of international humanitarian law, including aerial bombardments of civilian targets, indiscriminate bombings, artillery attacks on civilian-populated areas, reprisal killings of civilians and summary executions of prisoners.

The United Nations has imposed an arms embargo on the Taleban but has devoted few resources to monitor and enforce it. Even if it were effective, cutting military assistance to one side is playing favorites in a war in which all parties have been guilty of serious violations of international humanitarian law. A crucial step toward ending the human rights nightmare is an arms embargo on all the warring factions.

To really make a difference the embargo has to be coupled with other measures to punish those responsible for grave abuses. A first step is a prompt investigation of the massacre in Yakaolang by a small team of experts who can act efficiently before crucial evidence disappears.

Such measures would send the message to the war criminals and their victims that the world's concern for justice extends to them as well.

The writer, who recently visited Afghanistan for Human Rights Watch, contributed this comment to the International Herald Tribune.