Ten Afghan schoolchildren, two coalition service members and an Afghan police officer were killed Monday in a suicide bombing, officials said, and a land-mine explosion claimed the lives of seven Afghan civilians who were driving home after collecting firewood.

In Paktia province, a suicide bomber on a motorcycle detonated explosives near a busy market as a NATO coalition convoy passed by. Police officials said a nearby school had just dismissed students for lunch. In addition to the 10 children who were killed by the blast, many others were wounded.

Coalition officials confirmed that two service members were killed in the attack but did not identify their nationalities. Afghan officials said one local policeman also died.

Further north, in Laghman province, four women, two children and their driver died when their vehicle struck a land mine in the road, officials said. The group was returning from collecting firewood in the hills.

There were no immediate assertions of responsibility for the attacks, which come as Taliban insurgents have unleashed a wave of suicide bombings targeting the Afghan government and international agencies.

The insurgents have also littered the country’s roads with homemade land mines and roadside bombs.

The Taliban’s stepped-up campaign of attacks appears to be aimed at undermining upcoming national elections, and stability in general, as U.S. and NATO coalition forces begin to withdraw from the country.

Meanwhile, Taliban officials confirmed Monday that they had sent a delegation to neighboring Iran for three days of talks, signaling that Tehran could be seeking the role of regional mediator in negotiations to end Afghanistan’s 12-year war.

Taliban spokesman Qari Yousef Ahmadi said in an e-mail that emissaries from the Taliban’s political office met with Iranian officials over the weekend. The Iranian news agency confirmed the unprecedented meetings between the extremist Sunni Muslim Taliban and Iran’s Shiite government.

Peace talks between Afghan and Taliban officials have been stalled for months.