By Asif Shahzad and Charlotte Greenfield
WAZIRABAD, Pakistan (Reuters) - Moments before Pakistan's ousted Prime Minister Imran Khan was shot in the leg, a young man in the cheering crowd that lined the streets for a political protest spotted another man brandishing a pistol and raced at him to wrestle him down.
Ibtesam, hailed as hero by Khan's supporters for his actions, didn't get there in time to prevent the man firing, but said he might have prevented a more deadly outcome on Thursday from what Khan's aides say was an assassination attempt.
But nationwide protests that erupted on Friday after the attack point to more turmoil in a country with a history of deadly political violence as Khan's supporters push to get their leader, a former international cricket star turned politician who was ousted as premier in April, back into the top job.
Khan, 70, was shot while waving to rapturous crowds from atop a truck-mounted container from which he was leading a protest march to press for early elections.
Ibtesam, relating what happened next in a video shared later by activists from Khan's party, said: "I tried to overpower (the gunman) and push down his hand holding the pistol with my right hand, which threw off his aim."
Little was immediately known about Ibtesam, the man he tackled or whether there was more than one assailant. Videos from the scene echo with what sounds like an automatic weapon at the moment of the attack.
Police said they had arrested one suspected attacker and Prime Minister Shehbaz Sharif ordered an investigation.
Khan, who was ousted by a parliamentary no-confidence vote in April, and followers had been travelling around the eastern province of Punjab, launching a march a week ago in the city of Lahore with plans to enter the capital Islamabad next week.
Thursday's activities began at around 8 a.m. when supporters of Khan's PTI party gathered in the streets, with crowds swelling into the thousands throughout the day.
"Imran Khan arrived and we welcomed him, we never thought about any attack; people were chanting, workers were dancing,” said PTI supporter and witness Qadir Khan.
"When we started all of our workers and aides were in high spirits. It was jubilation that then turned into a tragedy."
In the late afternoon the march reached Wazirabad, a Punjab city famous for its production of cutlery. Khan, ringed by aides, stood atop a shipping container mounted on a truck as it wend its way slowly through swirling, festive crowds. Vehicles were adorned with petals and loud music was playing.
Gunfire suddenly rang out, clattering over the music, video footage showed. Those standing on the container ducked and Khan vanished from view.
"I heard a burst of shots after which I saw Imran Khan and his aides fall down on the truck," witness Qazzafi Butt said.
Below, panic and confusion ensued.
Some in the crowd around Khan's truck scrambled for cover while others tried to pinpoint and seize any assailants.
Video shared by local media showed a young man in a striped T-shirt lunging at an apparent shooter from behind, grabbing his right hand that clutched a handgun and tackling him as other PTI supporters closed in.
Reuters could not independently verify the footage.
"I snatched the pistol that fell on the ground, and he (tried to) escape and I chased and caught him and then came the police who took him into custody," Ibtesam said in the PTI video, wearing the same striped T-shirt.
Reuters was unable to reach Ibtesam by phone for further comment.
In the chaos and confusion touched off by the gunfire, supporters clamoured to know what had happened to Khan.
"PTI leaders started making announcements from the container, appealing for the people to calm down," a nearby shopkeeper told Reuters.
"Several people were injured and had blood all over their bodies. Some had their faces splashed with blood.
"People chanted that they would lay down their lives for Imran Khan," he added.
Officials and eyewitnesses said Khan was whisked to a safe location nearby and video showed him, with supporters crowding around, later clambering into a heavily guarded vehicle, but also waving to the throng.
"He was in high spirits. He told us that all is fine and no need to worry," said Qadir Khan.
Khan was taken to a hospital in Lahore where doctors said he underwent surgery on Thursday evening. Punjab Health Minister Dr Yasmeen Rashid said two bullets had hit Khan in the shin and thigh.
(Reporting by Asif Shahzad in Wazirabad and Charlotte Greenfield in Islamabad; additional reporting by Mubasher Bukhari and Gibran Peshimam; editing by Mark Heinrich)