A suicide bomber riding a bicycle targeted a police bus in Kabul on Sunday causing several injuries, officials told AFP, as early details of the attack were confirmed.
The attacker detonated his explosives on the Jalalabad road, a main route out of the Afghan capital and a regular scene of Taliban militant attacks in recent years.
Afghan interior ministry spokesman Sediq Sediqqi told AFP that six people were injured.
"A suicide bomber riding a bicycle targeted a police bus," he said. "According to our reports, six people were wounded in the attack."
Kabul police spokesman Hashmat Stanakzai confirmed details of the attack.
Eye witness Abdul Majeed, a stallkeeper at the scene, told AFP: "I saw a bicycle rider hit the bus and then heard an explosion."
The bus was left with broken windows but was not completely destroyed by the blast.
Kabul has seen a recent drop in attacks after a series of high-profile strikes in the first half of last year, with the National Directorate of Security (NDS) intelligence agency claiming to have foiled several plots involving truck bombs and suicide gunmen.
A series of attacks in 2013 targeted foreign compounds, the Supreme Court, the airport and the presidential palace in the city.
NATO forces are withdrawing from Afghanistan after more than a decade of fighting the Taliban, but negotiations have stalled on a security accord that would allow some US and NATO troops to stay after 2014.