China's Communist Party promised to deepen economic reforms to give the market a "decisive" role in allocating resources, state media reported Tuesday at the end of a closely-watched meeting.

The official Xinhua news agency announced the close of the gathering, known as the Third Plenum, which brings together the ruling party's full Central Committee and takes place amid intense security and secrecy.

It has traditionally set the economic tone for a new government, but analysts played down the significance of the declarations and Chinese social media users expressed disappointment.

"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," Xinhua cited a communique as saying, but did not give detailed measures.

China will "push forward land reform and give farmers more property rights", it said, including having one market for development land in both cities and the countryside.

"Both public and non-public sectors of the economy are important components of the socialist market economy and significant bases for economic and social development," Xinhua cited the document as saying.

It did not mention China's one-child policy, which had been trailed as a possible area for reform, and only obliquely addressed the divisive hukou residency system, which denies people who have migrated from the countryside to the cities equal access to benefits.

State broadcaster CCTV showed serried ranks of committee members seated at lines of desks in a cavernous hall, raising their hands in unison.

The 25 members of the party's Politburo sat in a row at the front, with General Secretary Xi Jinping in the middle, in front of a giant Communist hammer and sickle and 10 red flags.

Delegates were shown studiously reading their documents and taking notes.

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

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

Again it did not elaborate significantly.

"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.

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

But Wang Qinwei, China economist at Capital Economics in London, said the communique suggested agreement had yet to be reached on the details of reforms.

"It's more conservative than market expectations," Wang told AFP. "It's very broad on the market role.

"It mentioned some reforms, for example, fiscal reform, urban-rural land use, but the tone is very broad, giving people the feeling that concrete agreement may not have been reached," he added.

Chinese social media users were unimpressed.

"There are no breakthroughs at all," said one commentator on Sina Weibo, a Chinese version of Twitter. "What a disappointing announcement."

Another wrote: "Isn't this just meant to maintain the status quo?"

The plenum 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.

In a front-page editorial during the meeting, 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 said pressures for change are not yet strong enough to force radical reforms.

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