Updated

KABUL, Afghanistan (AP) — A suicide car bomber struck a convoy of NATO troops and Afghan police Thursday in northern Afghanistan, killing seven police officers and wounding at least 11 people.

The attack occurred in the early morning in Kunduz province's Imam Sahib district, according to an Interior Ministry statement. In addition to the deaths, six police and five civilians were wounded, the ministry said.

No NATO troops were killed in the bombing, said Maj. Michael Johnson, a NATO forces spokesman. He said some NATO forces were wounded, but declined to say how many or how seriously.

The vehicles were stopped in preparation of an operation in the area and the killed police officers had been standing outside of their trucks as they mobilized, said Abdul Rahman Aqtash, deputy police chief of Kunduz province

Taliban spokesman Zabiullah Mujahid claimed responsibility for the attack in a text message to The Associated Press. The insurgent group regularly launches attacks against military forces or government workers as part of their campaign against the government.

Kunduz and other northern provinces have become increasingly violent in recent months as insurgent activity has spread into areas beyond the militants' longtime bases in the south and east of the country. This expansion of militant attacks has happened even as the U.S. and its allies are rushing thousands of reinforcements to try to turn back the Taliban. The focus of U.S. and NATO operations has been in the ethnic Pashtun south.

On Tuesday, New Zealand suffered its first combat death of the Afghan war during a Taliban ambush in one of Afghanistan's most peaceful areas — the central province of Bamiyan.