BEIJING, May 14 (Xinhua) -- China's Internet watchdog has removed over 20 mobile apps with pornographic content in a campaign targeting irregularities in education apps.

The Cyberspace Administration of China (CAC) said Tuesday on its website that it had also shut down over 420 online columns and over 320 social media accounts. More than 55,000 articles with vulgar content irrelevant to education were also deleted.

The four-month campaign, launched in January by the CAC and other Chinese authorities including the Ministry of Education, came in response to social complaints about some mobile education apps with vulgar and pornographic content that severely damaged the physical and psychological health of teenagers.

The CAC vowed to continue to work with other authorities in regulating mobile education apps, and to handle complaints and tips-offs in a timely manner.