Police in the Afghan capital, Kabul, say at least one suicide bomber attacked a major hotel frequented by Westerners late Tuesday.
There was no immediate word on casualties, but witnesses said gunfire was heard in the vicinity of the hotel.
Earlier in the day, NATO said increasing numbers of male militants are dressing as women to escape capture from security forces in Afghanistan.
It said that in the latest instance, an Afghan and coalition force detained a senior militant leader who attempted to disguise himself as a female wearing a burqa .
The coalition says the Islamic Movement of Uzbekistan leader was taken into custody during an operation late Monday in the eastern province of Kunduz. The militant commander was responsible for planning attacks, including suicide bombings, against Afghan security forces.
In other violence Tuesday, NATO said separate insurgent attacks killed two of its service members.
And in southern Afghanistan, authorities said a roadside bomb killed two women and wounded a child in the Panjwai district of Kandahar province.