A suicide attacker blew himself up near the Kabul police academy on Friday, killing at least 20 recruits, in the second major attack in the Afghan capital in less than 24 hours.
The incident, which comes as cadets were returning to the academy after their two-day weekend, marks a serious breach of security at a premier training institute for Afghan security forces.
“A suicide bomber on foot blew himself up near the academy, heavy casualties are expected,” said Deputy Interior Ministry Spokesman Najib Danish.
The bomber was dressed in police uniform and managed to get close to a group of officers before detonating his explosives, another security official told AFP, requesting anonymity.
Heavily-armed security officials cordoned off the area and ambulances with wailing sirens were seen rushing to the scene.
Kabul Deputy Police Chief Gul Agha Rouhani confirmed the suicide attack but refused to comment on possible casualties.
The academy in west Kabul is a premier training institution for police forces in Afghanistan, with between 2,000 and 3,000 cadets graduating every year.
No group immediately claimed responsibility for the attack, which come as the Afghan Taliban step up their annual summer offensive despite a bitter power transition within the militant movement.
Earlier on Friday, a huge truck bomb struck the Afghan capital, the pre-dawn blast was near a Defence Ministry compound. All of the victims in the attack were civilians, including women and children.
The carnage comes a day after Taliban insurgents killed nine people in multiple attacks on police targets, including a truck bombing in the volatile eastern province of Logar.
The uptick in attacks highlight growing insecurity in the country amid a faltering peace process with the Taliban as Afghan forces face their first summer fighting season without full NATO support.
A UN report published Wednesday said civilian casualties in Afghanistan hit a record high in the first half of 2015.
The report said 1,592 civilians were killed, a six percent fall from last year, but the number of injured jumped four percent to 3,329.
Overall, casualties reached their highest level since the UN began issuing its authoritative reports in 2009.