Chinese police are speeding up the establishment of a national DNA database to help missing children find their parents as quickly as possible, the Ministry of Public Security (MPS) said on Tuesday.

"The DNA database has helped reunite 730 children with their families," Meng Qingtian, an official with the ministry's anti-trafficking office, told China Daily at an international forum on human trafficking hosted by the All China Women's Federation in Beijing on Tuesday.

The database has already collected 107,000 samples from lost children and 35,000 from the parents of missing children, she said.

The database is composed of blood samples taken by the police from missing children's parents, children suspected of having been abducted or with an unclear history, children in social welfare institutes, homeless children and child beggars, according to the ministry.

Information on the database is shared among the 236 DNA laboratories in the country.

"All homeless children must take blood tests before they can be adopted and this information will be included on the DNA database," Meng said. "Chinese children adopted by foreign families are also required to take the test."

It costs 100 yuan (US$14.8) to take a blood sample, while the cost of DNA tests vary. In Beijing, each DNA test costs at least 2,400 yuan, she said.

Police authorities cover the expense, so the service is free for parents and children.

During a nine-month anti-trafficking campaign, which began in April 2009, police rescued a total of 14,717 women and children, according to the ministry's latest data.

They arrested 17,528 suspects, including 19 who had a level A (most wanted) warrant against them.

About 30,000 to 60,000 children are reported missing every year in China, but it is hard to estimate how many are cases of human trafficking, the ministry said.

"The increasing number of trafficking cases in China is due to a large buyer's market and poor awareness of victims," Zhang Jing, a senior official of the All China Women's Federation, said at the forum on Tuesday.

Boys are especially in demand, because many Chinese families in rural areas want to have a son to carry on the family name, partially because the country's land allotment system is biased towards males.

In cities, the "incomplete social security system" places children in the migrant population at higher risk of being kidnapped, Meng said.

Since it is hard for them to enter kindergartens or schools in cities, they are easy prey for traffickers while their parents are busy working to earn money, she added.

Police across the country will treat all cases of missing women and children as crimes, setting up a special investigative team for each incident, in the latest bid to curb human trafficking, the MPS announced earlier this month.

The move, which follows the nine-month campaign against human trafficking, aims to allocate more manpower and resources to cases involving missing women and children.