Anyone charging a fee for H1N1 vaccinations will be punished, the National Development and Reform Commission said yesterday.

This comes two days after Health Minister Chen Zhu warned medical institutions across China carrying out the vaccination not to add any charge under any excuse to the inoculation, which is free and voluntary, the commission said in a notice.

The country initiated the inoculation program in late September and so far at least 5 million people have been vaccinated.

Special teams will inspect vaccination sites, including schools and clinics, the notice said.

The commission didn't say what punishment would be imposed.

Online criticism has accused some clinics of charging for vaccinations.

While dismissing the accusation on Monday, the Ministry of Health did concede that some clinics asked H1N1 vaccination recipients to also receive other paid vaccines.

Charging irregularities for H1N1 vaccinations exist in other forms.

In Ningxia, home to China's largest community of the Hui Muslim minority group, more than 2,000 Muslim pilgrims were vaccinated against H1N1, Xinhua News Agency reported in late last month.

Each person paid 5 yuan (73 cents) to cover "equipment costs", the report said, citing Ma Shouyu, head of religious affairs of Haiyuan, a county in the Ningxia Hui autonomous region.

The free H1N1 vaccination is funded by local governments, so poor areas are more likely to have such irregularities, said industry insiders.

In response, the central government has vowed to give poor western regions financial assistance to ensure vulnerable people are vaccinated for free.

As experts estimate that some 390 million people nationwide are at high risk of the potentially lethal pandemic while only 65 million might be vaccinated by the end of year, some complained about the shortage and unfair distribution which favors government officials.

Currently, the distribution plan for the limited vaccines is decided by local health authorities as the condition varies by region.

The Chinese mainland reported 51,490 H1N1 cases as of yesterday, including eight deaths.

China saw a sudden surge of flu cases since last month and experts have said that the pandemic will not wane until March.

Late last month, the United States declared H1N1 a national emergency while South Korea on Tuesday declared red alert, the highest level, against the pandemic.