A suicide bomber killed four people in the evening rush hour on Wednesday in a district of the Afghan capital near the national parliament, government ministries and the Russian embassy, a health ministry spokesman said.
It was the latest in a series of suicide attacks in Kabul that have coincided with renewed efforts to revive a peace process with Taliban insurgents that broke down in July.
At least 20 people were wounded in the bombing including women and children, Ministry of Public Health spokesman Ismail Kawusi said. Kabul police spokesman Basir Mujahid said the target of the attack on Darulaman Road remained unclear.
"Police are working to identify the victims of today's attack, but there was no military convey (in the area), they were all civilians," Interior Ministry spokesman Sediq Sediqqi said on his Twitter page.
A Russian Foreign Ministry source said the attack was not directed at its embassy, according to Interfax news agency.
There were no immediate claim of responsibility.
Since the start of the new year, Kabul has seen at least six bomb attacks. On Sunday, a rocket landed near the Italian embassy in Kabul, wounding two security guards.Envoys of Afghanistan, Pakistan, China and the United States met in Kabul this week to lay the ground for a negotiated end to 15 years of war, and urged the Taliban to join peace talks.