Nepal's King Gyanendra has marked the first anniversary of his royal coup by defending his seizure of power, amid fresh clashes with Maoist rebels.
Security forces are on alert in Kathmandu
In a national address on radio and television, the king said his coup had significantly weakened the rebellion.
Opposition politicians dismissed the speech, with one saying it would only lead to "further chaos".
Maoists staged overnight attacks which the army said killed at least seven police, four troops and four rebels.
One soldier was also killed near the capital.
The BBC's Charles Haviland in Kathmandu said there is little evidence to support the king's assertion that the insurgency is being put down.
King Gyanendra said the revolt was now limited to "petty crimes" and renewed a pledge to hold parliamentary polls by April 2007.
He said that during the past 12 months Nepal had been on the right track.
The king's address was shown on national TV
"Terrorist activities have narrowed down to just a few sporadic criminal activities," he said.
He dismissed a recent unilateral ceasefire called by the rebels, saying they had used it to regroup.
He said democracy was on the rise and urged Nepalis to take part in controversial town and city council elections scheduled for next Thursday.
"Free and fair elections will be conducted," he said.
"The elections are the only means to guarantee people's rights [and] consolidate democracy."
Human rights activists led demonstrations though Kathmandu, unfurling black flags and banners calling 1 February a "black day" for freedom.
Police beat some, arrested dozens and used water cannon, but let others march, our correspondent says. Reports said hundreds more people were rounded up around the country.
Authorities say at least 17 policemen and three soldiers were killed in attacks by rebels overnight in western Palpa district.
The army in western Nepal said rebels launched raids on armed forces and government posts in the town of Tansen.
A spokesman for the Maoist rebels said they had captured scores of soldiers and policemen as well as the district administrator, and confirmed they had suffered casualties in the attacks.
Government sources confirmed more than 140 people were missing.
Eyewitnesses said hundreds of rebels launched simultaneous attacks on government targets, including offices, barracks, jails and police posts.
Hundreds of pro-democracy activists were detained across the country on the eve of the first anniversary of the royal coup, according to the opposition.
They say next week's polls are aimed at entrenching an "illegitimate" royal regime.
The king sacked his government and seized executive powers on 1 February last year, accusing officials of having failed to suppress the Maoist rebellion.
He has been under pressure domestically and internationally to return the kingdom to democracy.
The Maoists recently abandoned a truce
In a strongly-worded statement, the US State Department said on Tuesday that "12 months of palace rule have only made the security situation more precarious".
Observers doubt free and fair elections can be held in Nepal, given the worsening security situation.
The Maoists have promised to disrupt the poll. They are blamed for killing at least one candidate, shooting and wounding another and kidnapping a third.
Many candidates have withdrawn following rebel threats, leaving about a quarter of the more than 4,000 seats with no one standing at all.