Mortar attack on major political gathering in Kabul kills three

A mortar attack on a large ceremony attended by Afghanistan's chief executive and other leading government figures in Kabul Thursday killed three people and injured 22 others, officials said.

The attack claimed by the Islamic State group represents a major security breach and marks a resumption of violence in the capital after weeks of calm amid ongoing peace talks between the US and Taliban in Doha.

"Stay calm, the area of the blast is far from us," said former lower house speaker Mohammad Younus Qanooni from the stage during a live broadcast of the outdoor event.

But moments after the announcement, another explosion and gunfire could be heard that sent people running.

A second unidentified voice then addressed the screaming crowd, saying: "I request my countrymen to stay calm. The mortar attack is far from the gathering."