The suspect, a university student, was picked up at a bus station in the city of Izmit in Kocaeli province which neighbours Istanbul, the agency said.

He was to be brought to Istanbul for questioning.

It was not immediately clear what his connection to the attack was alleged to be.

Officials said last week the police were still looking for the person who detonated the remote-control roadside bomb.

Ten people have been charged in connection with the attack so far.

A radical Kurdish militant group, the Kurdistan Freedom Falcons (TAK), claimed responsibility for the bomb which hit a bus carrying army personnel to work on June 22.

The blast killed five soldiers and the 17-year-old daughter of an officer and wounded 13 people.

The Turkish authorities say TAK is a front used by the Kurdistan Workers' Party (PKK), which has waged a bloody 26-year insurgency in the southeast. The PKK says TAK is a splinter group outside its control.

The bombing followed PKK threats of violence in urban areas after a wave of deadly attacks on the security forces in remote regions in the Kurdish-majority southeast.

Some 45,000 people have been killed since 1984 when the PKK, listed as a terrorist group by Turkey and much of the international, took up arms for self-rule in the southeast.