China's Communist Party ended a closely watched meeting Tuesday and approved a decision on "comprehensively deepening reforms", state media reported.

The official Xinhua news agency announced the close of the four-day meeting, known as the Third Plenum, which brings together all 376 members of the ruling party's Central Committee.

It takes place amid intense security and secrecy, and has traditionally set the economic tone for a new government.

A decision on "major issues concerning comprehensively deepening reforms" was approved and the market will play a "decisive" role in the allocation of resources, Xinhua said.

"The core issue is to properly handle the relationship between the government and the market so as to allow the market to play a decisive role in allocating resources and the government to better play its role," it cited a communique as saying.

China will "push forward land reform and give farmers more property rights", it said -- but did not give any specific measures.

A state security committee will be set up to "improve systems and strategies to ensure national security", Xinhua cited the document as saying, two weeks after a fiery attack in Tiananmen Square, the symbolic centre of the Chinese state.

The communique pointed out the need to "effectively prevent and end social disputes and improve public security", Xinhua said.

Again there were no details.

"The Party must give full play to its core role of commanding the whole situation and coordinating the efforts of all quarters, and improve the leadership and governance to ensure the success of reform," the agency added.

Xi Jinping, the party general secretary, delivered a "work report" to the meeting, Xinhua said.

The Third Plenum is seen as setting the course for the world's second largest economy over the next decade.

It comes a year after China embarked on a once-a-decade leadership change, with Xi taking over as party chief in November and then state president in March this year.

China has in the past used the meetings to signal major changes in policy, most notably in 1978 when it embarked on the landmark transformation from a Communist-style command economy into a key driver of global growth, trade and investment.

Over the course of the four-day meeting state media repeatedly raised the prospect of major economic changes.

In a front-page editorial, party mouthpiece the People's Daily praised past economic reforms for bringing prosperity to the world's most populous country and called for more.

But analysts have dampened expectations, saying they anticipate a broad blueprint instead, and that pressures for change are not yet strong enough to force radical reforms.

The economy in 2012 registered its worst growth rate for 13 years, expanding at an annual rate of 7.7 percent.