In the thick of maritime disputes with several of its neighbours, China on Tuesday said it is mapping South China Sea (SCS) with an aim to step up exploration for oil and gas and to reinforce its territorial claims.

China may step up its exploration of South China Sea to reinforce its territorial claims following announcement that geographical surveys of the area are underway, state-run ‘Global Times' reported.

"The majority of the disputed waters used to be beyond our reach because we seldom put our claims into action," Zhang Yunling, director of the Institute for International Studies under the Chinese Academy of Social Sciences, told the daily.

"By drawing a map, the country can reinforce its jurisdiction claim in the South China Sea, and further actions may follow, such as exploiting resources near the Nansha Islands," Zhang said.

Located south of China's coast, SCS is connected with narrow straits with Pacific Ocean and covers 3.5 million sq km of the ocean.

China claims the entire SCS as its own. Its claim however, has been contested by Vietnam, Philippines, Malaysia, Brunei and Taiwan which assert it is part their maritime waters.

Much to China's chagrin, the US extended tacit support to the small countries and stepped its presence in the Pacific region, calling for peaceful resolution of the disputes.

India's ONGC also drew Beijing's ire by taking up exploration in the blocks in SCS claimed by Vietnam.

According to a report released by China's National Administration of Surveying, Mapping and Geo-information (NASMG) a working group jointly set up by 13 government agencies will continue geographical surveying of the South China Sea and draw a map of the sea or its islands to "declare China's stance" on territorial issues. Similar mapping work will also be carried out on the Diaoyu Islands and other important areas in the East China Sea, (ECS) when the time is right, it said.

Diaoyu islands, known as Senkaku islands in Japan are currently under the administrative control of Tokyo which zealously reassert its control over the uninhabited islands.

Japan also prohibits fishing by Chinese there which resulted in several skirmishes in the recent times recently. "We are currently carrying out relevant work, and further details will be released at a proper time," an official with NASMG's map management office said.

China claims indisputable sovereignty of the Nansha and Xisha islands and their adjacent waters, but several countries in the region, such as Vietnam and the Philippines, have made competing claims.

Zheng Zemin, a researcher with the Hainan-based National Institute for SCS Studies, said that through the mapping, authorities may clarify the specific locations of the so-called "nine-dashed line" or "U-shape line" by setting their longitudes and latitudes. "A spat is inevitable but tensions are unlikely to escalate as maintaining cooperation despite disputes has been a basic consensus that China and relevant countries hold," Zhuang said.