May was the deadliest month for Afghan civilians since the United Nations started tracking deaths in 2007, according to a report released Saturday. The carnage continued, with bombs killing 21 people nationwide — including a family on a religious pilgrimage and a child lured by a suicide attacker pushing an ice cream cart.

Violence has been on the rise as the Taliban and other insurgents try to regain territory lost in the fall and winter to the U.S.-led coalition in southern Afghanistan. The insurgents have stepped up suicide attacks and bombings that are more likely to affect civilians.

Fighting always picks up in the spring after the opium poppy crop is harvested in the south and the snow melts elsewhere in the mountainous country, allowing insurgents to move more freely. But attacks have intensified as militants try to undermine confidence in the Afghan government, which wants to show it is ready to take over security as the U.S. begins to withdraw some forces.

"We are very concerned that civilian suffering will increase even more over the summer fighting season, which historically brings the highest numbers of civilian casualties. Parties to the conflict must increase their efforts to protect civilians now," said Georgette Gagnon, director of human rights for the U.N. mission in Afghanistan.

The U.N. said insurgents were responsible for 82 percent of the 368 civilians killed last month, with homemade bombs the leading cause of death. The international alliance and Afghan security forces were to blame for 12 percent of the deaths while it was not clear who was responsible for the remainder, according to the report. It also said 593 civilians were wounded last month.

NATO airstrikes, a frequent cause of tension between the Afghan government and the alliance, were behind 3 percent of civilian deaths, the report found.

Despite those findings, much of the public anger over civilian casualties has focused on the international force.

Last month, President Hamid Karzai ordered the alliance to stop bombing homes after an airstrike that accidentally killed a group of children and women in southern Helmand province. Coalition commanders apologized, saying the airstrike was launched after a gunbattle broke out following an insurgent attack on a patrol in the district that killed a U.S. Marine.

But the incident and Karzai's reaction has severely strained relations with the coalition and further complicated an already difficult relationship with the United States as President Barack Obama prepares a July troop drawdown in the increasingly unpopular war. Obama expressed his sorrow over recent civilian casualties in Afghanistan caused by coalition airstrikes in a videoconference with Karzai on Wednesday.

The death toll for international troops rose only slightly in May, with 56 killed compared with 51 the same month last year, according to an Associated Press tally.

The insurgency generally focuses its attacks on international and Afghan armed forces, but one of Saturday's attacks seemed designed to target children.

A suicide bomber pushing a red ice cream cart in the provincial capital of central Ghazni detonated his explosives, killing one and wounding three others, according to provincial police chief Mohammad Hussain.

"The suicide attacker was a young man with a thin beard and mustache wearing a scarf," said a witness who identified himself as Asadullah and said he was standing about 20 yards (meters) away when the blast occurred. "He was pushing an ice cream cart ... and then he exploded."

A roadside bomb also hit a minibus carrying a family to a shrine for a religious pilgrimage in the Khakrez district of Kandahar province in southern Afghanistan. The attack killed members of the family, including eight children and five women, according to provincial police chief Abdul Raziq. He said the bomb was planted by the Taliban and was intended for NATO or Afghan forces.

In the eastern province of Khost, a suicide bomber blew himself up outside the local police headquarters in the Shai Kali area, killing three policemen and a child, according to provincial police chief Sadar Mohammad Zazai.

Among the dead was a local police chief, Zazai said. It was not immediately clear whether he was specifically targeted. Provincial health director Hedayatullah Hamidi said 25 people were wounded in that attack.

The Taliban began its yearly spring offensive on April 30. The month that followed saw the most civilian deaths of any month since the U.N. started closely tracking casualties in 2007. Previously, the deadliest month was August 2008, with 341 deaths.

While the U.N. figures only go back to 2007, the monthly toll is likely the highest of the war because civilian casualties were not a major problem in its early years.

The international coalition has around 133,000 troops fighting in Afghanistan, including about 100,000 from the United States. On Saturday, NATO said a service member was killed in an insurgent attack in the south, bringing the total coalition deaths this month to 23. Since the start of the year, 229 have died.

Casualty figures blamed on the coalition and Afghan forces have been steadily declining over the past four years — despite an increase in allied and government forces. A recent U.N. report found that insurgents were responsible for 2,080 deaths in 2010 compared with 440 for the coalition and Afghan troops. That report found that deaths due to airstrikes declined by 52 percent last year compared with 2009.

The U.N., which is preparing a midyear civilian casualty report, said it decided to release the interim numbers Saturday because they were so high.

Karzai, meanwhile, was in Pakistan meeting with the country's political and military leadership in an effort to jump-start a faltering peace process with the Taliban, part of a reconciliation effort that he began last year. Many of the Taliban's key leaders are thought to be sheltering in Pakistan, and insurgents retain safe havens in the country's lawless tribal regions bordering Afghanistan.

"We both want stability in Afghanistan and in Pakistan," said Pakistani Prime Minister Yousuf Raza Gilani in a press conference held with Karzai following the first meeting of the joint peace commission. "Our only aim is to support the peace process, which is Afghan-led."

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