China's domain name system was under serial attacks starting from early Sunday, the China Internet Network Information Center (CNNIC) said, adding that the service is being resumed slowly.

The first round of attacks was repaired around 2 am. This was followed by a long-lasting and large-scale attack at around 4 am, said the CNNIC, naming it the largest in history against the national domain name service (DNS).

The logging service of some websites with the domain name of .cn and Sina Weibo were affected.

The CNNIC apologized to Net users in the country for the inconvenience that was caused and condemned the attacks.

An emergency plan has also been launched by the Ministry of Industry and Information Technology to ensure the nation's DNS safety.