ISTANBUL, Turkey, June 22 (UPI) -- A remote controlled roadside bomb killed four people and injured 15 in Istanbul, Turkey, Tuesday, officials said.
While no group has claimed responsibility for the attack, Turkish news reports indicated it may have been carried out by the militant Kurdistan Workers Party, The New York Times reported.
The organization, known by the initials PKK, seeks autonomy in southeastern Turkey, and has been listed as a terrorist organization by Turkey, the European Union and the United States.
Witnesses and police investigators said the explosion occurred during morning rush hour as a military bus traveled between a residential compound and office buildings housing the military police headquarters.
Turkish authorities say three sergeants and the 17-year-old daughter of a member of the security forces were killed in the attack in the city's European side, CNN reported.
"It was a remote-controlled, fragmentation bomb that was left on the side of the road," Istanbul Gov. Huseyin Avni Mutlu said. "This is a terrorist act."
Mutlu pledged to "hold firm" against terror attacks that try to "create an air of anxiety and hopelessness. We will do everything to our capacity to bring the perpetrators of this crime to justice."
