ISLAMABAD, Pakistan — In one of the most brazen attacks on foreigners in Pakistan in recent years, gunmen disguised as paramilitary police shot dead 10 tourists, including one American, and their Pakistani guide on a mountain-climbing expedition in the country’s rugged north, officials said.

The attack occurred at the foot of Pakistan’s second-highest peak, Nanga Parbat, highlighting the growing reach of Islamist militants in even the most remote areas. It is also likely to damage the country’s already struggling tourist industry.

A spokesman for the Pakistani Taliban claimed responsibility for the killings, which he said were in retaliation for American drone strikes in the tribal belt.

The dead included two Chinese, one Nepalese, an American citizen of Chinese origin and their Pakistani guide, according to Pakistani and American officials. The Ukrainian foreign ministry said five of its citizens had died, although Pakistani news reports put that figure at three and said that the victims included two Slovakians and a Lithuanian.