Thirty-seven Maoist rebels have been killed as security forces repelled a series of major attacks in Nepal's southern district, a Royal Nepal Army official said yesterday. One soldier and three policemen were also killed in the attack, CNN reported. It was the fiercest fighting between rebels and security forces since King Gyanendra took absolute power on February 1, saying that successive governments led by the political parties had failed to control the Maoist menace. The attacks took place as U.S. Assistant Secretary of State Christina Rocca arrived in Kathmandu on a three-day official visit during which she stressed that Nepal's Maoist rebellion poses a serious threat to regional security.