The device was attached to a bicycle and exploded as the bus passed during the morning rush hour, Kabul police criminal investigation department chief Alishah Paktiawal said. "It was a remote-controlled bomb fixed on a bicycle on the roadside, which targeted a ministry of interior police bus," he said. "More than 10 police are wounded. Two to three civilians who were in a taxi behind the bus are also wounded."
A purported spokesman for the Taliban, Yousuf Ahmadi, said that the extremist movement had been behind the attack. "Our mujahideen targeted a police bus with a remote-controlled bomb," he said, claiming that 14 police had been killed or wounded. The Taliban frequently exaggerate their casualty claims.
The blast blew out the windows of the bus and those of nearby shops were also shattered.
A shopkeeper said that he had seen several people hurt in the explosion, including his brother who had been outside the shop. "I was busy in my shop and suddenly heard a big bang followed by a big cloud of dust," said the man, who gave his name only as Sadiq. "When I came out of the shop, I saw my brother was wounded in his right arm and his leg. In the shop next door two friends were badly wounded, one with serious facial injuries - he is hard to recognize.
"I also helped two wounded civilians who had fallen into a ditch."
Kabul has seen an increase in terror attacks in recent weeks, with six deadly suicide bombs since the beginning of September and various other blasts, many targeted at police.
The attacks have killed at least five foreign troops and nearly 40 Afghans.
At the same time crime, including kidnapping for extortion, robbery and carjacking, has soared, making the city the least secure since the extremist Taliban were forced out in a US-led offensive five years ago.
A French general in charge of International Security Assistance Force (ISAF) troops in Kabul province said Monday that two bomb cells had been identified in the city.
The NATO-led ISAF was working with Afghan forces to "neutralize these two IED cells identified," Brigadier General Frank Le Bot told reporters.
He said that the increase in attacks appeared to be a result of military operations that had squeezed insurgents from their traditional strongholds in the east and south of the country.
Taliban and other forces wanted to keep "alive a permanent terror" in the city, Le Bot said, adding that he expected one or two improvised explosive device strikes a week.
This would enable the insurgents to say that the government and security forces "are not able to provide simply the security of the people, but if we are in charge in this country we are able to set the security," he said.
The US-led coalition that works alongside ISAF and the Afghan security forces said meanwhile that it arrested three men in a village near Kabul Tuesday who were "suspected suicide bomb facilitators."
Suicide bombings, similar to those seen in Iraq, have been on the rise in Afghanistan with nearly 100 across the country this year alone.
The attacks are usually claimed by the Taliban and have killed close to 200 people, most of them Afghan civilians.
In another incidents reported Tuesday, police in the southeastern province of Zabul said that troops killed two Taliban rebels in return fire Monday after the insurgents attacked ISAF and Afghan soldiers who were distributing food.
Two more were wounded as was an Afghan soldier, said Noor Mohammad Paktine, Zabul police chief.
© 2006 Agence France-Presse