BEIJING — Authorities have vowed to toughen a crackdown on illegal investment schemes after thousands of protesters took to the streets in central China at the weekend, state media reported Tuesday.

Demonstrators in Anyang, a city in Henan province, swarmed a train station on Sunday claiming they had been defrauded and threatening to take their gripes to Beijing, various reports said, in the latest protest to hit the country.

Photos posted online purportedly of the protest showed thousands of people and dozens of police, some wearing riot gear, on a street.