Afghan and US forces searching for a kidnapped election candidate have killed 13 suspected rebels and arrested another 40 in a raid on a Taliban hideout, local officials said yesterday.

The joint forces surrounded the rebel den between the districts of Ghorak and Khakrez in the southern province of Kandahar on Sunday, said defence ministry spokesman General Mohammed Zahir Azimi.

"We arrested 40 Taliban in the area after a gunbattle," he said. He said there were no US or Afghan casualties and he had no details of the toll on the Taliban side.

The insurgents, meanwhile, launched a fresh spate of guerrilla-style strikes this weekend, sparking fierce battles that killed a district police chief, seven officers, an election candidate and three others, officials said.

More than 1,100 people have been killed in the past six months, and US military commanders believe the violence may worsen as rebels step up attacks with legislative elections just two weeks away, the next key step toward democracy after a quarter century of fighting.

UN spokesman Adrian Edwards told The Associated Press that some of the world body's agencies had urged some employees to take vacation during the elections because of fears of violence, though he noted that the official UN alert level had not changed."The United Nations continues to monitor the security situation," he said.