The Pakistani military blocked a convoy carrying thousands of Pakistanis and a small contingent of U.S. anti-war activists from entering a lawless tribal region along the border with Afghanistan on Sunday to protest American drone strikes.

The group, led by cricket star turned politician Imran Khan and his political party, was turned back just miles from the border of South Waziristan. After an hour of fruitless negotiations, Khan announced that the caravan would backtrack to the city of Tank, about 15 kilometres away. There, he delivered a speech to the crowd of about 10,000.

Khan has harshly criticized the Pakistani government's co-operation with Washington in the fight against Islamist militants. He has been especially outspoken against U.S. drone strikes targeting militants and has argued that the country's alliance with Washington is the main reason Pakistan is facing a homegrown Taliban insurgency. He has suggested before that militant activity in Pakistan's tribal areas will dissipate when the U.S. ends the war across the border in Afghanistan.

"We want to give a message to America that the more you carry out drone attacks, the more people will hate you," Khan told the crowd.

The anti-American sentiment, always high in Pakistan, was evident in the crowd that waved banners saying "Down with America," and "The friend of America is the traitor of the nation."

Pakistan's tribal regions, such as North and South Waziristan, border Afghanistan and serve as bases for militant groups such as the Taliban to stage raids across the border into Afghanistan.

The protest convoy of about 150 cars set out on Saturday from the capital Islamabad, travelled 400 kilometres and then stopped overnight in the city of Dera Ismail Khan. The plan for the second and final day was to travel another 120 kilometres to reach Kotkai in South Waziristan. But the military stopped the convoy in the town of Kawar.

Khan told the rally that they wanted to continue their journey to Kotkai, but the army said it was too late, and going inside South Waziristan at night was dangerous. Khan said he didn't want to put his supporters in danger, so he turned the rally around to Tank.

Drones terrorize peaceful tribes

Regardless of whether he was able to enter the tribal region, Khan portrayed the two-day motorcade as a success.

"We have taken the voice of the people of Waziristan to the world," he said.

Thousands of supporters had turned out along the route to cheer on the convoy, which stretched about 15 kilometres, including accompanying media. Some of those packed into the vehicles waved flags for Khan's political group and chanted: "We want peace."

Video on Pakistani media showed barricades with hundreds of police in riot gear, a sign of concerns that the motorcade would be attacked or become unruly.

Around three dozen Americans from the U.S.-based anti-war group CODEPINK joined Khan for the march. The American protesters say the U.S. drone strikes, contrary to the claims of American officials, have terrorized peaceful tribes living along the border and killed.

The convoy aimed to throw a spotlight on the drone attacks, which many Pakistanis oppose as violations of the country's sovereignty that often kill civilians. The U.S. says its drone strikes are necessary to battle militants that Pakistan has been unable or unwilling to control.

South Waziristan is a tribal region where the Pakistani military has been battling a violent uprising by the Taliban, and factions of the Taliban threatened to attack the march. On Saturday, a statement from a Taliban faction said to be based in eastern Punjab province warned that militants would target the protesters with suicide bombings.

Area near Waziristan (Google map)