KABUL, Afghanistan - A NATO airstrike targeting insurgents inadvertently hit two civilian homes in the volatile southwestern Helmand province, killing 14 women and children, an Afghan government official said Sunday.

Dawood Ahmadi, a spokesman for the provincial government, said the alliance launched the airstrike late on Saturday in retaliation for an attack earlier in the day on a US Marine base in Helmand's northwest district of Nawzad. He said NATO hit two civilian houses, killing five girls, seven boys, and two women.

NATO spokesman Maj. Tim James said a joint coalition and Afghan delegation was traveling Sunday to the site to investigate. He didn't confirm the aistrike and provided no details about it or the attack on the Marines.

Civilian deaths are an ongoing source of tension between NATO and Afghan officials.

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Afghan President Hamid Karzai has repeatedly called on coalition forces to minimize night raids and airstrikes in order to avoid accidental deaths.

Helmand borders Pakistan and is an insurgent bastion. The province's vast poppy fields, especially in the north, are the Taliban's prime profit center.

Afghan insurgents have stepped up a spring offensive across Afghanistan.

On Saturday, a Taliban suicide bomber wearing a police uniform blew himself up inside a heavily guarded compound in northern Afghanistan as top Afghan and international officials were leaving a meeting.

The blast killed two senior Afghan police commanders and wounded a German general in command of coalition troops in the region. Two German soldiers and two other Afghans were also killed in the blast that came just weeks before a planned drawdown of US troops begins this summer.

The bomber detonated his explosives-laden vest inside the governor's complex in Takhar province, where high-ranking Afghan officials were meeting with members of the international coalition, according to Faiz Mohammad Tawhedi, a spokesman for the governor.

Among the dead was Gen. Daud Daud, regional police commander in northern Afghanistan. Daud was a former deputy interior minister for counternarcotics and a former bodyguard of Ahmad Shah Massoud, the charismatic Tajik leader who commanded the Northern Alliance and died in an al-Qaida suicide bombing two days before the September 11, 2001, attacks that provoked the US invasion.

Also killed were provincial police chief Gen. Shah Jahan Noori, a secretary to the governor and one of Daud's bodyguards, the health director said.

Gen. Markus Kneip, the NATO force's commander for nine northern provinces, was among the wounded, German Defense Minister Thomas de Maiziere said in Berlin.

Fifty-one German troops have been killed in Afghanistan since the start of the war.

Also Saturday, Karzai ordered that only Afghan troops _ not NATO forces _ should carry out special operations and night raids and that the international coalition should not conduct any raids that have not been coordinated beforehand with Afghan authorities.

The move was aimed at quelling popular anger over what the raids, which many Afghans say cause civilian casualties, capture the wrong people or mistreat civilians during searches of private homes and compounds. It wasn't immediately clear what impact, if any, Karzai's orders would have on NATO's actions.

The coalition has defended the raids as a necessity to flush out insurgents from their hideouts.