A general view of the Istanbul police station, at left, where a Turkish police officer was killed following a suicide attack. (Associated Press)
Turkey's state-run news agency says authorities were questioning six people, including some foreigners, in connection with a suicide bombing at an Istanbul police station.
Last week's attack killed an officer and wounded another. The female bomber was also killed.
The Anadolu Agency said the suspects were being questioned by anti-terrorism authorities in Istanbul on Tuesday. It gave no further detail on the suspects.
Some Turkish media have said the bomber was a Russian citizen of Chechen origin.
A leftist group had claimed responsibility for the January 6 bombing, but later retracted its claim saying it had mistakenly concluded that the bombing was the work of its members.