Police in Southwest China's Yunnan province have captured a man suspected of murdering six members of his family.

Chen Wenfa, 21, was arrested on Monday in mountains near his village in Luquan Yi and Miao autonomous county, said a spokesman of Kunming public security bureau in the provincial capital.

Chen is suspected of killing his parents, grandmother, uncle, uncle's wife and his cousin on Nov 16 at their courtyard in Wumeng village.

He sought help at the Kunming Psychiatric Hospital in August and was diagnosed with acute schizophrenia before leaving the facility, the spokesman said.

The murders were the third case in a week of mass killings by someone suspected of being mentally ill, following incidents in Inner Mongolia and Beijing.

"Although this is a special case, it reveals the deficiency in treating and caring for schizophrenic patients," said Xia Lingxiang, a psychology professor from Southwest University in Chongqing.

Xia said care of such people, especially in rural areas where medical facilities are lacking, is inadequate.

Often patients do not cooperate in their treatment.

"They refuse to take medicine, and family members tend not to be harsh on them," Xia said.

Patients may have hallucinations and family members, because they are so close by, can be mistaken for someone else and attacked, Xia said.

"To solve the problem, a medical system that ensures treatment and a lot of investment is needed," said Xia.

The latest incident follows two similar mass killings.

Wen Tiequan, a villager from Huhhot, Inner Mongolia, killed himself in a mountain cave after he was named as the chief suspect in the Nov 26 stabbings of six villagers.

Police said Wen had mental problems but had not undergone treatment because his family was too poor and because they did not take his illness seriously.

Li Lei, 29, a restaurant owner in Daxing district, Beijing, killed his parents, wife, sister and two children on Nov 23. He later told police he carried out the killings after long-term hostility toward his harsh parents and "controlling" wife.

Experts have suggested Li might have been suffering from a mental illness.

A Ministry of Health official said in September more than 56 million patients with various mental illnesses in China had not received treatment. Only a quarter of patients with serious mental disorders are hospitalized.

A lack of awareness about mental illness and economic pressure are the main reasons why so many go untreated, said Wang Gaohua, who is with the mental illness research center of the People's Hospital affiliated to Wuhan University.

Mental illness accounts for 20 percent of all diseases in the country and has become a serious threat to public health and stability. The rate is expected to rise to 25 percent by 2020, according to the Ministry of Health.

Many experts have called for national legislation to tackle the challenges of mental illness in the hope of assuring timely, appropriate and affordable medical intervention.

The latest figures show there are 11 hospital beds and fewer than two psychiatrists for every 100,000 people, far less than the world average of 43 beds and four doctors.