BEIJING (AP) — Chinese microblog operators have been ordered by regulators to tighten censorship after the country's most popular service was criticized for failing to block prohibited material.

The regulator announced Friday that operators will be required to set up a mechanism to scan postings for false information and to keep closer track of what users post.

Last weekend, Sina Weibo was ordered to suspend some services for one week after authorities accused it of allowing material promoting "wrong public opinion orientation," obscenity and "ethnic discrimination."