Former Pakistan prime minister Imran Khan has been wounded in the shin when his convoy was shot at in the country's east, an aide says.
A member of Khan's Pakistan Tehreek-e-Insaf (PTI) party said several colleagues were also wounded amid reports one had been killed.
"A man opened fire with an automatic weapon. Several people are wounded. Imran Khan is also injured," Asad Umar told Reuters.
Khan was taken to hospital.
The attack happened in Wazirabad, nearly 200km from the capital Islamabad.
Former cricketer Khan, 70, was leading a protest march on Islamabad to demand snap elections.
There were hundreds of people in the convoy.
A bullet hit his shin, PTI spokesman Fawad Chaudhry said.
"Imran Khan and (party colleague) Faisal Javed received bullets wounds. A bullet hit IK's shin. Both have been taken to hospital for treatment," Chaudhry told Reuters.
Javed, who had blood stains on his clothes, told Geo TV from the hospital that "several of our colleagues are wounded. We heard that one of them is dead".
Prime Minister Shehbaz Sharif condemned the shooting and ordered the interior minister to seek an immediate investigation.
Since being ousted in April through a parliamentary vote, Khan has held rallies across Pakistan, stirring opposition against a government that is struggling to bring the economy out of the crisis that Khan's administration left it in.
Khan had planned to lead the motorised caravan slowly northwards up the Grand Trunk Road to Islamabad, drawing more support along the way before entering the capital.
"I want that all of you participate. This is not for politics or personal gain, or to topple the government... this is to bring genuine freedom to the country," Khan said in a video message on the eve of the march.