China is expanding its coast guard fleet to better protect the country's maritime rights, the State Oceanic Administration said on Thursday.

The country will speed up the construction of 20 inspection ships this year and plans to purchase patrol ships and planes, the agency's director Liu Cigui said at its annual conference on Thursday.

A new inspection ship joined a Chinese fleet patrolling the South China Sea on Jan 10, and more are expected to join soon. The 4,000-ton vessel is the first ship to join the fleet since the China Maritime Police Bureau was established in July.

The bureau is a consolidation of the China Maritime Surveillance, the coast guard force of the Ministry of Public Security, the fishery law enforcement command of the Ministry of Agriculture and the maritime anti-smuggling authorities of the General Administration of Customs.

The consolidation has brought 16,300 of the country's maritime law enforcement personnel under one agency, according to the SOA's restructuring plan published in July.

With more countries challenging China's territorial rights in recent years, the country has been strengthening its maritime law enforcement capacity to better safeguard its interests.

Last year, China Maritime Surveillance carried out 36 patrol trips and 402 flights, according to the SOA. The patrol trips, which spent 262 days at sea, detected 188 foreign ships and 21 foreign planes that intruded upon China's maritime territory.

After Tokyo announced its intention to "purchase" and "nationalize" China's Diaoyu Islands in September, Chinese fleets were sent out 50 times to patrol the islands' waters. In the South China Sea, Vietnam, Malaysia, the Philippines and Brunei have competing claims over several Chinese islands.

Wang Hanling, a maritime law specialist at the Chinese Academy of Social Sciences, said increasing pressure on China's maritime law enforcement has created the need to build more ships.

"China's ability to protect its maritime rights lags far behind Japan and South Korea," Wang said.

Besides improving maritime law enforcement, Liu said detention areas will be constructed for ships seized for illegally sailing in Chinese waters.

Qi Jianguo, former Chinese ambassador to Vietnam, said these moves demonstrate China's determination to prepare itself for complicated maritime disputes.

The country's maritime economy is booming and revenues reached 5.4 trillion yuan ($871 billion) last year, an increase of 7.9 percent from the previous year, the SOA said.