BEIJING (AP) - The U.N. or another independent body should be asked to investigate the killing by police of villagers protesting the seizure of land for a power plant in southern China, a U.S.-based human rights group said Thursday.

Human Rights Watch said an independent and transparent investigation into the Dec. 6 shootings in Dongzhou, a village northeast of Hong Kong in Guangdong province, is "urgently needed."

The government says three people were killed in the incident, while residents put the toll as high as 20.

"Unfortunately, China has no record of conducting credible and transparent investigations into the actions of its security forces," the group's Asia director, Brad Adams, said in a statement.

Human Rights Watch urged China to "immediately invite the United Nations or another independent body to investigate the killings."

China rejected the group's call.

"The relevant Chinese authorities will deal with this matter according to law," Foreign Ministry spokesman Qin Gang said Thursday.

Villagers say the protest erupted over complaints that residents received little or no compensation for land taken by the government for construction of a power plant.

The violence last week was the deadliest clash yet in a series of confrontations throughout China between police and villagers angered by land seizures for the construction of factories, shopping malls and other projects.

A petition posted on the Web by a group of Chinese activists and academics has also called for an inquiry into the shootings.

Human rights groups have compared the violence in Dongzhou to the 1989 Tiananmen killings.

But Chinese Foreign Ministry spokesman Qin Gang on Tuesday rejected that comparison, saying that it was still too early to draw conclusions about the Dongzhou incident.

China's government says the nonviolent Tiananmen protests were an anti-government riot that had to be crushed by force. Hundreds, perhaps thousands, of people were killed when the military attacked the pro-democracy protesters in central Beijing.

President Hu Jintao's government has made a priority of trying to improve the lives of the 800 million people in China's countryside, many of whom have missed out on the country's 25-year-old economic boom.