Pakistani politician and former cricketer Imran Khan was rushed to hospital with head injuries on Tuesday after falling off a lift taking him onto the stage for an election rally.
Television footage showed Khan, leader of the Pakistan Movement for Justice party (PTI), bleeding from the head as he was carried by aides through the crowd at the event in Pakistan's second largest city Lahore.
The dramatic development came at the end of a day that saw 17 people killed and dozens more wounded in bomb attacks in northwest Pakistan, taking the death toll in the bloody campaign for Saturday's general election past 100.
The poll will mark a democratic milestone in a country ruled for half its history by the military as the first time a civilian government has served a full term and handed over to another through the ballot box.
Khan, who won only one seat in 2002 and boycotted polls in 2008, has led an electric campaign, galvanising the middle class and young people in what he has called a "tsunami" of support that will propel him into office.
The 60-year-old, who has undertaken a punishing schedule of daily rallies but who is known for his physical fitness, tumbled from a riser along with several of his staff, seemingly after one of them lost their balance.
Witness Raza Zaidi told AFP that Khan was being lifted on a crane with five people but lost his balance and fell when a sixth one tried to climb up. Khan hit the lifter before falling on the ground.
"Imran Khan has one head injury. We are conducting his CT scan and other tests. He is stable, he is conscious and he is recognising people. He is alright," Faisal Sultan, the director of Shaukat Khanam hospital, told reporters.
People at the rally venue, where thousands had gathered, expressed sadness.
"Passion and love for Imran Khan brought all these people here. We are still here, all we can do is pray now," said Sobia Khan, a PTI supporter.
PTI spokeswoman Shirin Mazari said Khan was injured on his forehead after falling from a height of more than seven feet (over two metres), but was conscious.
Party officials had initially said Khan would be back to address the rally, but he was later transferred from a small private hospital to the Shaukat Khanam cancer hospital he set up in honour of his mother for specialist treatment.
Television images showed Khan being transported on a stretcher, his head swathed in bandages.
Hundreds of well wishers and party supporters gathered outside the hospital, chanting "Long Live Imran Khan", an AFP reporter said.
Khan's main rival, former prime minister Nawaz Sharif tipped to win the election, conveyed his sympathies over Khan's fall and was praying for his early recovery, his Pakistan Mulsim League-N party spokesman Siddiqul Farooq said.