KATHMANDU, Aug 20: Maoist rebels who have cut off Kathmandu for three days attacked security forces and bombed buildings inside the Nepalese capital on Friday, as the government partially agreed to guerrilla demands for lifting the blockade.

The government said it would investigate and make public within 30 days the whereabouts of an unspecified number of leftist activists who have disappeared in the Himalayan kingdom's increasingly deadly civil war.

The acceptance of a key rebel demand came after the blockade, which has been enforced mostly through fear, turned violent for the first time. Two rebels opened fire on police and soldiers guarding Kathmandu's Land Registration office soon after the building was badly damaged by a bomb, said Deputy Superintendent of Police Ganesh K.C.

The rebels then fled. One police officer was injured in the attack and taken to hospital where he was in serious condition, the superintendent said. The attack prompted staff to close down the office, which had remained open despite the blockade that has stalled transport links and sent prices soaring in the city of 1.5 million people.

Another bomb exploded at an empty police post on the outskirts of Kathmandu on Friday and caused no injuries, police said. The Maoists, who have taken over vast swathes of the countryside in their eight-year war to overthrow the monarchy, announced the blockade of the capital after their threats, including a bombing at a top hotel, led some 24 major companies to shut down.

Information Minister Mohammad Mohsin appealed for normality in Kathmandu and said the government would probe the whereabouts of missing Maoists and trade union activists. "We will make public the results of our investigation within 30 days," Mohsin told reporters. But he had no comment on other key demands of the Maoists, including the delisting of the rebels as a terrorist group. The government made the classification after the guerrillas broke a ceasefire last year.

An activist in contact with the Maoists said the rebels were pressing the blockade in hopes of removing the terrorist label and forcing peace talks immediately - as the guerrillas believe recent weeks have put them in a strong negotiating position.

"The government is fully prepared to hold new peace talks, but the Maoists are not serious about the peace and security of this country," the information minister said. Another official said the government would likely only delist the Maoists as terrorists as a compromise in formal negotiations.

Troops were posted every 500 to 1,000 metres along highways and were also in the lush hills around Kathmandu, which has been relatively unscathed by the civil war that has claimed nearly 10,000 lives since 1996.

The army urged residents to defy the strike. "We want to tell vehicle owners to be free from this slavery mentality of terror created by rebel threats," army spokesman Rajendra Bahadur Thapa said. "We want to assure them we have enough security to protect them." -AFP