Pakistan has summoned the acting US ambassador and lodged a protest over continued CIA drone strikes in its tribal belt bordering Afghanistan, saying that the attacks were "unlawful" and violation of the country's sovereignty.
US Charge d'Affairs Richard Hoagland was called to the Foreign Ministry and "officially conveyed the government's serious concern regarding drone strikes in Pakistani territory", an official statement said.
Hoagland was informed that the "drone strikes were unlawful, against international law and a violation of Pakistan's sovereignty".
Pakistan's parliament has "emphatically stated that (the drone strikes) were unacceptable" and that they "represented a clear red-line for Pakistan", the statement said.
The US has carried out eight drone strikes in Pakistan's tribal belt since a crucial NATO Summit on Afghanistan ended in Chicago on May 21. The attack on Monday killed 15 militants in Pakistan's turbulent northwest.
The US intensified the drone campaign shortly after Pakistan did not make any announcement at the summit about ending a six-month blockade of supply routes to Afghanistan.
The supply lines were shut after a cross-border NATO air strike killed 24 Pakistani soldiers in November last year.
Most of the drone strikes were carried out in North Waziristan Agency, though a few attacks focussed on South Waziristan, where the Pakistan Army conducted an operation to flush out the Taliban three years ago.
Pakistan has repeatedly criticised the drone strikes, calling them counter-productive.
A second and separate demarche was lodged with Hoagland regarding the seizure of "unauthorized weapons" from the possession of three US diplomats in the northwestern city of Peshawar on Monday.
Hoagland was informed that the "carrying of unauthorised weapons by diplomats was unacceptable and contrary to both Pakistani law and accepted norms of diplomatic conduct".
Three US diplomats were briefly detained after police found automatic weapons and pistols in their possession.
Three Pakistan employees of the US Consulate in Peshawar were arrested in connection with the same incident.
A court in Peshawar on Tuesday rejected the security bonds submitted for the three Pakistani employees and asked them to submit fresh bonds.
Pakistani-US relations plunged to a low last year after a CIA contractor shot dead two Pakistanis in Lahore, an American raid killed Al Qaeda chief Osama bin Laden, and the NATO air strike killed 24 Pakistani soldiers.