(Adds ministers' sons, Halkbank offices searched)
ISTANBUL, Dec 17 (Reuters) - Turkish police detained the sons of three cabinet ministers as part of an investigation into alleged bribery linked to public tenders on Tuesday, Turkish newspapers reported on Tuesday.
Police carried out dawn raids in the main commercial city Istanbul, detaining at least 18 people including well-known businessmen, and also searched the headquarters of state-run lender Halkbank in the capital Ankara, sources said.
Hurriyet and other newspaper websites reported that the sons of Interior Minister Muammer Guler, Economy Minister Zafer Caglayan and Environment and City Planning Minister Erdogan Bayraktar were detained.
Government officials could not immediately be reached for comment. Police declined to comment on the reports.
It was not immediately clear if there was a link between the investigation at Halkbank's offices in the capital Ankara and the reported detentions.
Halkbank shares fell as much as five percent after reports of the police search emerged. Halkbank officials could not immediately be reached for comment.
Police also searched the headquarters of construction magnate Ali Agaoglu's Agaoglu Group, its chief executive Hasan Rahvali told Reuters.
(Reporting by Seda Sezer, Orhan Coskun, Birsen Altayli; Writing by Daren Butler; Editing by Nick Tattersall, John Stonestreet, Alister Doyle)