A powerful explosion destroyed a minibus carrying people to work during Monday's rush hour in downtown Kabul, killing at least one of the passengers. At least 19 people were injured, four of them women. 

"There has been an explosion against a minibus in Kabul," local police spokesman Basir Mujahid told AFP news agency. "Police are investigating the nature of the explosion."

Officials believe that the blast was likely caused by a roadside bomb, not a suicide attacker.

On Twitter, interior ministry spokesman Sediq Sediqqi said that "Kabul Police have arrested 3 suspects related to an explosion in Taimani," referring to the Taimani neighborhood where the attack took place. 

Pictures on social media showed the smoking wreck of a bus with roughly 20 seats.

This is the fifth attack carried out in the Afghan capital this year. Five days ago, Islamic State terrorists stormed Afghanistan's largest military hospital, killing dozens of staff, security and patients. Two weeks ago, Taliban gunmen and suicide bombers killed at least 23 people when they carried out attacks on a police station and a secret service bureau.

Also on Monday, state security forces stormed a prison in southern Afghanistan held by the Taliban. In the Chah Mirza village in the Helmland provice, 32 civilians and police officers were freed. 

The security situation in Afghanistan has long been difficult, with state troops struggling to contain extremist Islamic groups - primarily the Taliban, but also the "Islamic State" (IS) militant group - since the NATO-led coalition ended its combat mission in 2014. Though Kabul controls the main provincial centers, less than 60 percent of the country is currently under the control of the government.

mb/rc (AFP, AP, dpa)