A veteran CNN reporter was detained by police Saturday while reporting live at the renewed anti-government protests at Taksim Square in Istanbul. The reporter, Ivan Watson, who has been based in Istanbul for 12 years, was released approximately 30 minutes later after police were satisfied with his press credentials.

“Turkish police detained me and my crew in the middle of a live report in Taksim Square,” Watson tweeted shortly after the incident, adding that “one officer kneed me in the butt.”

He later tweeted, “Turkish police released [the] CNN team after half an hour. Officer apologized for another officer who kneed me while I was being detained.”

The police demanded to see his press credentials, but the “Turkish police officer wasn’t satisfied with my press card from [the] prime ministry” and demanded a passport, also, because “many are counterfeited,” Watson told CNN.

Watson’s live broadcast on CNN International was disrupted by the detention, as the cameras kept filming during the confrontation. Reportedly, during the interaction police broke the microphone off the camera used during the broadcast.

According to a write-up of the incident in CNN International, the request by authorities for a passport to prove press credentials is considered very unusual, and has never before been necessary in Watson’s 12 years of working in Istanbul.

Shortly after Watson’s detention, Turkish police fired tear gas and water cannons at hundreds of demonstrators in Istanbul and Ankara who were marking a year since the start of anti-government protests.

Last year, police clashed with protesters In Taksim Square, leaving eight dead and thousands injured. Riot police also deployed tear gas and water cannon to disperse some 1,000 people in the capital Ankara, who hurled fireworks.

There were no reports of loss of life in this weekend’s protests, but dozens were injured and 70 arrested by security forces.

In the run-up to the Saturday anniversary, Prime Minister Recep Tayyip Erdogan had warned authorities would do “whatever is necessary” to curb the protests.

Security was tight around Taksim Square and other points in Istanbul, with some 25,000 police deployed, streets to the square blocked and public transport curtailed.

AFP contributed to this report.