Civilian deaths attributed to pro-government forces rose in the first quarter of this year even as overall civilian casualties dropped to their lowest level in that period since 2013.

The United Nations said in its quarterly report that pro-government forces were responsible for 53 percent of civilian deaths. But insurgents were responsible for the majority — 54 percent — of all civilian casualties, which include deaths and injuries, even though the number of suicide bombings decreased compared with the same period in 2018, the report said.

During the first three months of this year, military operations escalated as both sides sought leverage in peace talks between the United States and the Taliban in Doha, Qatar. At the same time, there has been a relative lull in insurgent suicide attacks that indiscriminately kill civilians, especially in Kabul, the capital. The city has been a repeated target during the conflict, which is in its 18th year.

“It is unclear whether the decrease in civilian casualties was influenced by any measures taken by parties to the conflict to better protect civilians, or by the ongoing talks between parties to the conflict,” the United Nations report said.

The agency reported 581 civilians killed and 1,192 wounded during the first quarter, a 23 percent decrease in overall casualties compared with the same period in 2018.

Other quarterly numbers may reflect an increasing reliance on airstrikes in a war in which Afghan security forces tend to hunker down in fortified bases rather than mount aggressive assaults against Taliban fighters. When attacked, Afghan forces often call for airstrikes by the American-trained Afghan Air Force to dislodge the enemy.

Aerial operations were the third-highest cause of civilian casualties, killing 145 civilians and wounding 83 during the quarter — a 41 percent increase for those type of casualties compared with the same quarter in 2018. The report attributed almost all of those casualties to American airstrikes.

“A shocking number of civilians continue to be killed and maimed each day,” Tadamichi Yamamoto, the United Nations secretary general’s special representative for Afghanistan, said in a statement. “All parties must do more to safeguard civilians.”