More Sarajevo Shelling Kills 9 and Wounds 30 : Balkans: Four children are among victims as rebel Serbs continue intensified shelling of Bosnian capital. Youngsters were playing outdoors on a sunny day.

Nine people, including four children who had ventured outdoors to play, were killed Sunday in mortar and sniper attacks on a city desperate to free itself from 38 months of Bosnian Serb siege.

Six people were killed when a shell slammed into a downtown neighborhood near the central market, which had been crowded earlier in the day with shoppers enjoying a respite from fighting and rainstorms.

Among the dead there were three children, including two little girls in summer dresses. A jump rope lay in a pool of blood at the grassy scene.

Three people were killed elsewhere, including a 16-year-old boy killed by a shell in a Sarajevo suburb and a young man who was shot to death by a sniper as he rode his bicycle past French U.N. peacekeepers in a notorious sniper area near the presidency building.

In addition to the nine people killed Sunday, 30 were wounded, bringing the toll of civilian casualties in the capital to more than 50 dead and 180 injured in nine days, according to government statistics.

Bosnian Serb attacks on civilians intensified in retaliation for a government army offensive launched to relieve the siege of Sarajevo. The government campaign made modest gains, but Serbs now claim to have recaptured lost territory.

Neither side’s assertions about the fighting can be verified, but the civilian toll in Sarajevo is clear.

“The indiscriminate bombing of cities is unacceptable,” an international humanitarian aid official said Sunday. “We are trapped in a terrible game: The military makes gains, the civilians pay.”

In their recent escalation, Bosnian Serbs have shelled hospitals, apartment buildings and lines of people waiting for water. Lining up for water has become a ritual in the capital of Bosnia-Herzegovina ever since the Serbs cut off electricity, water and gas to the city more than a month ago.

Another ritual is for children to play in basements and shelters, safe from the bombings and gunfire. But Sunday, sunshine broke out after several gray, cold days, and the fighting seemed to have subsided. Some children had ventured outside to play.

The escalation of attacks on the city coincided with the decision by the U.N. peacekeeping force to relinquish heavy weapons to the Bosnian Serbs. The weapons had been confiscated from the Serbs and warehoused as part of a plan to protect Sarajevo by creating a weapons-exclusion zone within a 12-mile radius of the city.

But the United Nations gave up on the effort after the Serbs took more than 370 peacekeepers hostage last month. The weapons-exclusion zone was created after a 1994 incident similar to the Sunday attack when a mortar hit a marketplace, killing 68 people.