Turkey holds 5 over Ankara bombing, hits PKK in Iraq

The arrests came just hours before another suicide attack in a busy Istanbul shopping street which killed four and wounded 20, the city governor said.

It was not immediately clear whether the bomber, who was also killed, was listed among the four dead.

The five people arrested overnight stand accused of "an attack on Turkish unity and on the Turkish people," Anatolia said, citing an Ankara court which ordered the detentions.

The arrests came as Turkish airforce planes continued to bomb outlawed Kurdistan Workers' Party (PKK) hideouts in mountains across the Iraqi border, an army statement said.

The army said 30 planes took part in the bombings which hit the area around Sinat and Haftanin and Gara.

The Kurdistan Freedom Falcons (TAK), a radical Kurdish group with ties to the PKK, claimed responsibility for the March 13 blast.

Turkish officials accuse the group of being a front for attacks by the PKK, which is listed as a terror group by Ankara and its Western allies and which launched an insurgency against the Turkish state in 1984 targeting greater autonomy for Kurds.