A suicide bomber blew himself up in the Afghan capital of Kabul on Monday, killing at least six people near a police checkpoint, including policemen, officials said, but no militant group has yet claimed responsibility.
Six people were killed in the explosion, said Najib Danish, a spokesman for the interior ministry. Ten policemen and civilians, including women, were injured in the blast.
The attacker on foot detonated his suicide vest close to the checkpoint near a school in central Kabul, which is in the same area as the finance and justice ministries and close to the presidential palace.
Police spokesman Basir Mujahid said he was about 20 metres (66 ft) away from the blast, near where a demonstration had broken up some 30 minutes before.
"I took four bodies away but there were more on the ground," he said, without giving further details.
Hundreds of protesters, including university students, had taken to the streets of Kabul to demand the deployment of reinforcements to Hazara-dominated districts in Ghazni province which have been attacked by the Taliban.
The explosion came as Afghan security forces have been suffering scores of casualties in heavy fighting with Taliban militants in two provinces.