KATHMANDU (Reuters) - Dozens of protesters were injured on Friday as police used teargas and batons at a rally in Kathmandu to demand King Gyanendra fires the loyalist prime minister, witnesses and party officials said.

Nepal, battling a bloody Maoist revolt against the constitutional monarchy, is in political turmoil since the king sacked an elected government in October 2002 and replaced it with a staunch monarchist cabinet.

Organisers said more than 30 protesters including top party leaders were detained and dozens were wounded in the scuffle with police.

"Long live democracy. Correct the regressive step," shouted the protesters as riot police sprayed water from fire engines and used batons to disperse the crowd in the heart of the capital.

Home Ministry spokesman Gopendra Bahadur Pandey said 26 people detained during the protest were later freed.

"It was an unprovoked act by the police," Subash Nemwang, member of the Communist Unified Marxist-Leninist (UML) party, second biggest of the five groups, told Reuters.

Five parties have called for a general strike in the Nepali capital on Monday to protest against the police action against what they called a peaceful protest.

The crisis is the latest in Nepal fighting to quell a seven-year Maoist revolt. Maoists are campaigning to set up a communist republic in the world's only Hindu kingdom tucked between Asian giants, China and India.

The Maoist insurgency has claimed more than 8,700 lives so far and crippled the aid and tourist dependent economy as well as threatened the stability of the multi-party democracy set up in 1990.