The Philippines and Vietnam are "hijacking" the regional bloc Asean to enlist support for their rival claims in the South China Sea, stirring up trouble for China with its neighbours, according to a book published by a government think tank in Beijing.
The series of reports by the China Institute of International Studies also said countries outside the region such as the United States were making it easier for Hanoi and Manila to exploit Asean and create division and uncertainty.
The book examining China's relations with its neighbours comes as Beijing has become increasingly embroiled in territorial disputes in the East and South China Seas.
A Vietnamese ship was severely damaged in a collision with a Chinese boat in the South China Sea on Sunday, the latest in a series of clashes since China set up an oil rig off the disputed Paracel Islands last month. Tensions over the oil rig caused anti-Chinese riots in Vietnam last month.
Several countries in the region have territorial claims in the South China Sea, including China, Vietnam, the Philippines, Malaysia, Taiwan and Brunei.
The think tank studies said some claimants wanted disputes to be dealt with by Asean, forcing the regional bloc to take sides.
Huang Guifang, a former Chinese ambassador to the Philippines, said Vietnam and the government in Manila were trying to isolate China in Asean, but Beijing could counter their influence.
"After all, Asean nations will have to consider their national interests rather than just following those two nations," he said.
The involvement of the US in the South China Sea dispute only complicates the situation and will also make it easier for nations such as Vietnam and the Philippines to hijack the regional bloc and create divisions, another report in the book said.
"At the same time, external forces are stepping up efforts to lure Asean to contain fast-developing China, creating uncertainties in China-Asean relations," it said.
The United States has strongly criticised China's actions in the South China Sea. US Defence Secretary Chuck Hagel said at a security forum that Beijing was destabilising the region by aggressively pushing its territorial claims.
The Philippines is pressing its claims in the South China Sea at an international tribunal.
On relations with Japan, the reports said the "provocation" by Japanese Prime Minister Shinzo Abe in visiting the Yasukuni Shrine that honours war criminals last December had damaged Sino-Japanese ties.
China has been stepping up its engagement with its neighbouring countries since last year, upgrading its ties with Malaysia to a comprehensive strategic partnership.