A suicide bomber blew himself up in the middle of a demonstration against corruption in Afghanistan's eastern province of Khost on 2 April, killing 17 people and injuring at least 50 more, government officials said.

Violence has escalated in Afghanistan as most foreign troops withdrew in 2014 and last year was the worst on record, with more than 10,000 civilian casualties, according to the United Nations.

There was no immediate claim of responsibility and it was unclear whether the attack was linked to the insurgency led by the Afghan Taliban, an Islamist militant group.

"A suicide bomber detonated his explosives among the crowd of people near the Governor's house. I saw many people were killed and injured in the blast, also Humayun Humayn, a member of the Afghan parliament, was among the injured," said Rahmanullah Khan who witnessed the attack.

Khost Police Chief Faizullah Ghairat confirmed that one of the organisers, outspoken lawmaker Humayun, was wounded in the attack. Although the police chief did not describe his condition, other officials said Humayun had lost both his legs.