ISLAMABAD (Reuters) -- Pakistan has summoned the U.S. ambassador to protest over missile strikes by pilotless U.S. aircraft on the Pakistani side of its border with Afghanistan, a Pakistani government spokesman said.
The protest came two day after missiles fired by a suspected U.S. drone killed up to 20 militants in the volatile South Waziristan border region.
"It was underscored to the ambassador that the government of Pakistan strongly condemns the missile attacks which resulted in the loss of precious lives and property," a Foreign Ministry spokesman said in a statement. "It was emphasized that such attacks were violation of Pakistan's sovereignty and should be stopped immediately."
Frustrated by an intensifying insurgency in Afghanistan, U.S. forces have stepped up attacks on militants on the Pakistani side of the border with more than a dozen missile strikes and a commando raid since the beginning of September.
No senior Al-Qaeda or Taliban commanders have been reported killed in the attacks.
U.S. Ambassador Anne Patterson had previously been summoned to the Foreign Ministry last month after a cross-border ground assault by U.S. commandos on September 3.
Senior U.S. officials have spoken of respect for Pakistani sovereignty but have declined to rule out more strikes.
Pakistan, an important ally in the U.S.-led war on terror, is also battling militants on its side of the border but it says cross-border U.S. strikes undermine its efforts to isolate the militants and build support for government policy against them.
The upper house Senate adopted a resolution this week condemning cross-border missile attacks by the U.S. drones.