(CNN) -- A Pakistani politician critical of U.S. drone strikes says American authorities detained and questioned him at a Canadian airport Friday night.
Imran Khan, a former cricket star, this month led a march to the border of Pakistan's tribal region to protest U.S. drone strikes.
On Friday, he had boarded a plane in Toronto bound for New York, but was removed from the plane and interrogated on his views on drones, Khan wrote on his Twitter account.
"My stance is known. Drone strikes must stop," Khan wrote.
The politician was questioned for two hours, said Arif Alvi, secretary general of Khan's party, Tehreek-e-Insaf, in a Twitter post.
Khan said he missed his flight.
The U.S. Department of Homeland Security did not immediately comment on the alleged incident.
Khan has been a fierce critic of U.S. policy in Pakistan and the use of drone strikes, calling them a violation of Pakistan's sovereignty and a strategy that stokes militant anger towards Washington.
In recent years, the U.S. government has sharply stepped up the use of drone attacks in Pakistan's mostly ungoverned tribal region, widely believed to be a safe haven for militant groups fueling the insurgency in Afghanistan. U.S. officials say the drone strikes are an effective strategy against militant groups and insist civilian casualties are rare.