Villages were cordoned off and thousands of police kept watch along roads in central China on Tuesday following riots between majority Han Chinese and a Muslim minority that killed seven people and injured 42.

People in the area have been told they could leave only for emergencies, said the head of a mosque in the village of Nanren near the fighting's epicenter in Henan province (search).

"I didn't step out of the mosque the entire time. I only heard that people from our village got into a fight with Han while passing a neighboring village," said the imam, who refused to give his name.

Martial law was lifted over the area on Monday, the imam said, but "we're still being told not to leave unless we absolutely have to."

He said two of the dead in the rioting were from Nanren, a village of about 5,000 people.

Uniformed officers and members of the paramilitary People's Armed Police (search) stood guard across the poor, densely populated farming region surrounding the village of Langchenggang (search) where rioting broke out last Wednesday.

Up to 5,000 joined in weekend battles, fighting with clubs and burning houses, according to residents interviewed by phone.

The origin of the disturbance is still unclear, although residents and the government said it involved a traffic accident between Han and their neighbors from the Hui Muslim minority (search).

The government's Xinhua News Agency on Monday released a brief report on its international service saying seven people were dead, but didn't say what ethnic groups they came from.

Xinhua said the violence began after a traffic dispute between a man from Nanren and another from the nearby town of Nanwei. Eighteen people have been arrested over the clashes, it said.

Others reached by phone said fighting began after three Hui men in a car beat up a 17-year-old Han boy who blocked the street. They said large scale clashes broke out after the arrival of a group of 400-500 Hui from a nearby town.

Government notices posted around the area said only that "conflicts between people" had led to deaths and injuries, cut off roads, and destroyed homes and vehicles. The notices demanded those involved turn themselves in by Tuesday and offered rewards for information on crime-doers.

Descendants of ethnic Chinese who converted to Islam generations ago, the Hui have clashed throughout history with the Hans who make up more than 90 percent of China's 1.3 billion people. Hui armies in the 18th and 19th centuries held out for years against Qing Dynasty suppression campaigns.

With the loosening of communist authority in the countryside in recent years, religious and economic tensions between Hui and the Han or other ethnic groups have occasionally boiled over into violence. The communist government suppresses most information about such incidents.

In December 2000, at least five Hui were shot and killed by police during protests in the eastern province of Shandong after a dispute over a Han butcher advertising "Muslim pork." Muslim dietary laws forbid the eating of pork.

Official newspapers on Tuesday made no mention of the fighting in Henan and police and government officials in Henan refused to answer questions.

Residents and officials have not confirmed a report by The New York Times that as many as 148 people had been killed in the fighting.

Along the road to Langchenggang, a Hui woman peeling garlic outside her Muslim halal restaurant said Han frequently use their superior numbers in the area to discriminate against Hui businesses.

"The Han were all ganging up on Hui villagers. Then the police did too little to intervene and just let the fighting go on," said the woman, who gave only her surname, Ba.