ISTANBUL (Reuters) - Turkish police on Wednesday stormed the offices of an opposition media firm days ahead of an election, in a crackdown on companies linked to a U.S.-based cleric and foe of President Tayyip Erdogan, live footage showed.

Brawls broke out and police sprayed water to disperse dozens of people in front of the offices of Kanalturk and Bugun TV in Istanbul, a live broadcast on Bugun's website showed.

The media groups are owned by Koza Ipek Holding, which has links to Islamic preacher Fethullah Gulen. The authorities on Tuesday took over management of 22 companies owned by Koza Ipek.

Erdogan has led a crackdown against once influential followers of Gulen, his former ally, after police and prosecutors seen as sympathetic to the cleric opened a corruption investigation into Erdogan's inner circle in 2013.

A prosecutor is seeking a prison sentence of up to 34 years for Gulen, 74, on allegations that he ran a "parallel" structure within state institutions that sought to topple Erdogan, who has led Turkey, first as prime minister, then president, since 2003.