No one immediately claimed responsibility for the separate bombing and shooting in the Afghan capital.

The Taliban issued a quick statement denying any responsibility for the attack.

The 9/11 anniversary is a sensitive day in Afghanistan’s capital and one on which attacks have occurred.

The Taliban claimed the attack, which came as the insurgents were holding their latest round of talks with U.S. envoy Zalmay Khalilzad in the Gulf state of Qatar, where they have a political office.

The first bomb was attached to bus carrying university students, and was followed 20 minutes later by two roadside bombs in the same area.

According to Basir Mujahid, spokesman for the Kabul police chief, the bomber was on foot and detonated his vest full of explosive after he was spotted by police.

A coordinated double suicide bombing by the Islamic State group hit central Kabul on Monday morning, killing at least 25 people, including nine journalists, officials said. An AFP photographer and a cameraman for a local TV station were among the fatalities, the police said.

The Islamic State group affiliate in Afghanistan has claimed responsibility.

Suicide bombers attacked two mosques in Afghanistan on Friday, killing at least 72 people including children.

The powerful explosion rocked the neighbourhood, which is considered the city’s safest, during the peak of morning rush hour.