By Anthony Boadle

BRASILIA (Reuters) - Angry residents of the Brazilian border town of Pacaraima ran riot and drove out Venezuelan immigrants on Saturday after a local restaurant owner was stabbed and beaten, residents and government officials said.

The demonstrations forced hundreds of Venezuelans to flee back across the frontier on foot and residents set fire to the belongings they left behind and to tires to block the only road crossing between the two countries, video images released by the state of Roraima government showed.

The outburst of anger was sparked by the robbery and severe beating of a resident in his home on Friday night by four Venezuelans, Roraima state security secretary Giuliana Castro said by telephone.

The four Venezuelan suspects stole 23,000 reais ($5,800) from the restaurant owner, identified only as Raimundo. He suffered head injuries and was taken to hospital unconscious but was reported to be out of danger, said Castro, who is also head of the state's police force.

After crossing back into their country, Venezuelans migrants attacked a group of 30 Brazilians who were shopping across the border and who had to be taken to a shelter, Castro said.

Venezuela's government expressed concern about reports of attacks on its citizens and a "massive eviction" of Venezuelans, and asked Brazil to guarantee their safety. A foreign ministry statement said the violence was fueled by xenophobia.

Tens of thousands of Venezuelans have poured over the border into Roraima state over the last few years, fleeing economic and political turmoil in their country. The influx has overwhelmed the state's social services and brought a rise in crime, prostitution and disease, and has sparked incidents of xenophobia, Brazilian government officials say.

A Pacaraima resident who asked to be identified only as Ismael said by telephone that the four Venezuelans allegedly entered the restaurant owner's home, tied him and his wife up and stabbed and beat the man severely before robbing his house.

"The people here are up in arms. They are burning the belonging of Venezuelans who were camped out here," Ismael said. He said police were looking for the four men.

"Out, out, out! Go back to Venezuela," demonstrators shouted at the Venezuelans as they rushed passed the border post carrying what they could, video images distributed by the Roraima government showed.

Brazilian army soldiers stationed at Pacaraima to help maintain order asked Venezuelan immigrants to return across the border for their own safety, Castro said.

Venezuela's economy has been in steep decline and there are periodic waves of protests against the leftist government of President Nicolas Maduro. Maduro argues that he is the victim of a Washington-led "economic war" designed to sabotage his administration through sanctions and price-gouging.

"The only people responsible for this tragedy are Maduro and his gang," tweeted Venezuelan opposition politician Ismael Garcia about the flare-up in Brazil.

The Roraima government has declared the immigration influx a social crisis and asked Brazil's federal government to close the border, which it will not do for humanitarian reasons.

The Brazilian government said late on Saturday that it was sending more troops to Pacaraima to back up border police.

(Reporting by Anthony Boadle in Brasilia; Additional reporting by Alexandra Ulmer in Caracas; Editing by Frances Kerry and Sandra Maler)