The mayor of Istanbul, Ekrem Imamoglu, one of Turkey’s most prominent opposition politicians, was arrested on Wednesday morning on charges related to corruption and terrorism, the city’s prosecutor’s office said.

A large group of police officers arrived at Mr. Imamoglu’s house and took him away, and a number of his aides were also detained. Prosecutors said arrest warrants had been issued for more than 100 people.

Mr. Imamoglu has been seen as a likely contender in the next presidential election, scheduled for 2028, although early elections are likely. He and other opposition figures have accused President Recep Tayyip Erdogan’s government of seeking to exclude Mr. Imamoglu from politics so that he cannot run in the election, possibly against Mr. Erdogan himself.

In a video posted on social media before his arrest, Mr. Imamoglu accused the government of “usurping the will of the people.”

“We are facing great tyranny, but I want you to know that I will not be discouraged,” he said.

This is a developing story.