BEIJING - Social unrest, driven by abuses of power and a growing wealth gap, is on the increase in China, according to one of the country's leading think tanks.

China's rapid economic rise in recent years has come at a cost, and protests by those left behind or abused by newly rich officials have been on the increase.

Officials from the Chinese Academy of Social Sciences said this week, when releasing a report on the problem, that China's leaders have to deal with this growing resentment against power abuses.

"China currently continues to be stuck in a phase of frequent conflicts. Social unrest has been on the rise compared to last year," Chen Guangjin, a co-author of the report, told a news conference on Monday.

CASS is connected to the government and is China's top think-tank

on social issues.

Chen said environmental issues are among trends connected with protests, with growing unhappiness over the pollution that has come with China's economic expansion.

"Six of the 10 top environmental protection incidents that have happened in China since 2001 took place in 2009," Chen said.

Chen did not give any overall numbers, but tens of thousands of protests take place in China every year, including incidents that can impact large cities.

Li Peilin, another co-author of the report, said unrest also stemmed from land grabs, a common problem where local officials seize property for redevelopment and give little or no compensation.

Chen said other widespread protests flared up in 2009, included strikes by taxi drivers in several large cities. Such work stoppages partially shut down nearly a half dozen cities across the country last summer, including the mega-city of Chongqing and the southern island resort of Sanya. The drivers were upset at rising costs and tighter licensing regulations.