China will spend $111.6 billion on its police forces in 2012, the government said Monday, as it focuses on quelling rising social unrest ahead of a 10-yearly leadership change.

Despite nearly two decades of annual double-digit economic growth, social stability in China has remained a challenge due to massive urbanisation, rising expectations and a widening gap between rich and poor.

Public security spending will increase by 11.5 percent to 701.7 billion yuan, more than the 670 billion yuan earmarked for national defence, the finance ministry said in its 2012 budget.

The announcement came after Premier Wen Jiabao listed the challenges facing his government and pledged to maintain stability in his annual report to the National People's Congress (NPC), China's parliament.

"Problems concerning land expropriation, housing demolition, workplace safety, food and drug safety, and income distribution are still very serious and the people are still very concerned about them," Wen said.

"To promote harmony, we will properly balance reform, development and stability, effectively defuse various types of conflicts, risks and dangers, prevent isolated problems from growing into major ones and promote social harmony and stability."

Wen also pledged to crack down on corruption, another key cause of social unrest.

Maintaining stability is a key priority for the Communist Party ahead of a 10-yearly leadership transition that will see President Hu Jintao, Wen and other top leaders stepping down from their party posts this year.

Last year, police forces in China were placed on high alert following the uprisings against authoritarian governments in the Arab world.

Public security spending in China covers police, state security, paramilitary police, courts and jails.

According to studies published by the China Academy of Social Sciences, the numbers of "mass incidents," or public protests, in China grew from 8,700 in 1993 to more than 90,000 in 2006.

Such incidents range from protests involving only a few dozen people to large street demonstrations with thousands of protesters.