Imran Khan leads thousands in Karachi rally, calling for an end to strikes seen as violation of Pakistan's territory.
Imran Khan, Pakistan's cricket-great-turned-politician and the chairman of the Tehreek-e-Insaf party (Movement for Justice), has led around 6,000 protesters in Karachi demanding an end to US drone strikes on Pakistani soil.
On Saturday, thousands of anti-US protesters gathered near the port of Pakistan's largest city Karachi to stage a protest on the first of the planned two-day sit-in against what they regard as violations of Pakistan's territory by the US and NATO forces.
Khan called for the blocking of NATO's supply line to put a stop to the unpopular drone attacks which are carried out mainly in Pakistan's tribal regions, where al-Qaeda and Taliban fighters are believed to be based.
US-Pakistani relations are at a low point over the unilateral American raid that killed Osama bin Laden in the Pakistani garrison city of Abbottabad.
Pakistan is angry that it was not told in advance of the raid and says it did not know that the al-Qaeda chief was hiding in the area.
In the wake of the operation in which Bin Laden was killed, Pakistan's parliament has demanded that the US stop its missile strikes and drone attacks, warning that it may cut off the supply route into Afghanistan altogether if the attacks do not end.
Dawn, Pakistan's leading English daily, reported that Khan said that the "war on terror" is not Pakistan's war and it is harming the country's integrity, and that drone and other such attacks were breeding terrorism.
Imran Khan said that the Pakistani government is complicit in carrying out the drone attacks.
"On the face of it they always condemned drone attacks but under hand they have given the Americans permission," Khan said before joining the sit-in in the port area.
"Twice the parliament has passed resolutions condemning drone attacks and each time within 24 hours there have been drone attacks.
"So there is total disregard to the democratic representatives of Pakistan, and thirdly, it is violation of all humanitarian laws, it violates every human law because no law allows anyone to become judge, jury and executioner.
"It is a fixed match between the government, army and America," he said.
He added the protest would convey to the US that "we will not be cowed down by drone attacks".
Khan further demanded that new midterm elections be held saying that the Pakistani government should resign "if they can't stop it".