Former Prime Minister Nawaz Sharif landed in Pakistan on Monday on his return from exile to lead a campaign to topple the country's US-allied military ruler who ousted him in a coup eight years ago.
Black-uniformed commandos entered the Pakistan International Airlines jetliner after it landed at Islamabad airport and surrounded Sharif, who refused to hand over his passport to immigration officials who were also on the plane, a reporter said.
Before leaving London on Sunday evening, Sharif warned that President Gen. Pervez Musharraf's government might try to arrest or deport him.
Interior Ministry spokesman Brig. Javed Iqbal Cheema said Sharif "would be treated according to the law" on his arrival. He declined to elaborate.