The demonstrators on Sunday defied a daytime curfew despite warnings that violators could be shot, opposition parties said.
Nepal's royal government extended a daytime curfew to several cities outside the capital on Sunday after opposition parties vowed to go ahead with a pro-democracy rally despite warnings.
And on Monday, the government declared a curfew between 11am and 6pm for the third consecutive day.
A second death was reported on Sunday among demonstrators demanding that King Gyanandra give up the absolute powers he seized 14 months ago. Police said dozens had been arrested.
In Kathmandu, an opposition spokesman said thousands of people were on the streets in small groups despite the curfew and tight security.
At least 12 protesters have been rounded up and as many injured during clashes with police in the capital, said Rajendra Pandey, of the Communist Party of Nepal (Unified Marxist Leninist).
In Boudha, on the outskirts of Kathmandu, about 1,500 protesters demanded the restoration of democracy and chanted anti-royal slogans. Others blocked roads throughout the capital with burning tyres while police used tear gas to disperse them, a police officer said.
"We are trying to resist and contain them," said the police officer, who did not want to be identified. He said at least 50 people had been arrested on Sunday.
A Kathmandu Hospital doctor said a 17-year-old man had been wounded by a rubber bullet fired by police.
Hundreds of protesters violated
the curfew outside Kathmandu
In the southwest town of Bharatpur, witnesses said about 2,000 protesters clashed with police firing tear gas after a woman died overnight from injuries suffered in a demonstration.
Three people, including the woman, were wounded at Narayanghat, about 150km from Kathmandu, when soldiers fired at protesters demanding King Gyanendra end his absolute rule.
It was the second death in shooting by government forces on protesters during the four-day anti-monarchy strike across the poor Himalayan kingdom that started on Thursday.
In the western tourist resort town of Pokhara, 200km from Kathmandu, thousands of people tried to storm a state hospital where the body of a man shot dead by soldiers on Saturday was taken, witnesses said.
The crowd burned some security posts in the area and clashed with riot police.
The government has said it
will shoot protesters on sight
"Thousands of people are out on the streets. There is high tension here," said Keshav Lamichhane, a journalist from Pokhara.
The curfew covers Butwal and Taulihawa in the southwest, where at least 11 Maoist rebels and three security men were killed during clashes on Friday night.
Bharatpur, 220km southwest of Kathmandu, was also under curfew a day after 25,000 protesters went on a rampage that left dozens injured, police said.