A Foreign Ministry spokesman defended recent naval activity by China on Friday, describing the activities of patrol boats located near the Diaoyu Islands as "lawful."

"Our law enforcement vessels patrolled waters close to the Diaoyu Islands to maintain normal order and safeguard China's maritime rights and interests," spokesman Liu Weimin said during a routine press conference.

Liu reiterated that the Diaoyu Islands and its adjacent islets are part of China's territory.

The State Oceanic Administration (SOA) issued a statement Friday saying that two of its surveillance ships, the Haijian 50 and Haijian 66, arrived in the area early Friday morning to conduct an inspection tour.

The patrol by China Marine Surveillance (CMS), a maritime comprehensive law enforcement agency under the SOA, has demonstrated Chinese government's consistent stand of its sovereignty on the mentioned islands, according to a SOA statement regarding the patrol.

The CMS is tasked with safeguarding China's marine rights and interests in accordance with laws and regulations, the statement noted.

With approval from the State Council, or China's Cabinet, the SOA and the Ministry of Civil Affairs earlier this month publicized the standard names of the Diaoyu Island and 70 adjacent islets, which have been part of inherent Chinese territory since ancient time and over which China has indisputable sovereignty.

The Diaoyu Island is about 356 kilometers from the city of Wenzhou, 385 kilometers from the city of Fuzhou and 190 kilometers from the city of Keelung.

The CMS began routine patrol and law enforcement missions in the sea areas within China's territory on July 20, 2006. It conducted patrol near the Diaoyu Islands and adjacent islets on Dec. 8, 2008.