HUBLI, Indi — Nepal's Maoist rebels called for a three-day nationwide general strike starting today while the U.S. and United Nations both expressed dismay after the king of Nepal yesterday dismissed a democratically elected government and assumed power amid a growing civil war.

King Gyanendra fired Prime Minister Sher Bahadur Deuba, declared a state of emergency, assumed power for the next three years and put a number of politicians under house arrest, saying the multi-party government had failed to hold elections or defeat the Maoist insurgency that has spread to nearly every corner of the picturesque Himalayan nation.

"We're deeply troubled by the apparent step back from democracy in Nepal," State Department spokesman Richard Boucher said.

In New York, U.N. chief spokesman Fred Eckhard, speaking for Secretary-General Kofi Annan, said: "The Secretary-General is deeply concerned at the actions taken by the constitutional monarchy in Nepal yesterday to dissolve the government, impose a state of emergency, and suspend civil liberties and freedom of expression."

International air service was suspended, phone and Internet connections were cut and the army was reported to be patrolling streets in the capital of Katmandu.

In a rare televised address, Gyanendra, 58, said he had decided to dissolve the government — the second time he has done so in the past three years — and would form a new cabinet under his leadership.

The action added to the sense in the region that Nepal is in a downward spiral, with no clear path toward repairing its dysfunctional politics or bringing an end to the violence that has claimed an estimated 10,000 lives since the Maoists launched their "people's war" in 1996.

Gyanendra's announcement poses a policy challenge for the United States, which has provided Nepali security forces with about $22 million in light weaponry and other forms of military aid during the past several years. Human rights groups have condemned both sides in the conflict for widespread abuses, but U.S. officials have justified the aid on the grounds that without it, the Maoists might win — and Nepal could join the roster of failed states hospitable to terrorism.

The conflict is also of deep concern to neighboring India, which is waging its own struggle against Maoist rebels — some with links to the Nepali insurgents — in a number of eastern states and has provided Nepal with military aid. In a strongly worded statement yesterday, India's Foreign Ministry condemned Gyanendra's announcement as "a serious setback to the cause of democracy in Nepal" and "a cause of grave concern."

India had been trying to convince the king to form a front with political parties against the Maoists, and one analyst described the king's decision as a "snub" for India, Nepal's largest trading partner.

With no phone or Internet links to Katmandu, details of the situation there were sketchy. A New Delhi-based Western diplomat who spoke with a colleague in Katmandu yesterday afternoon said the colleague had described the city as "relatively calm," with streets filled with traffic and shops operating normally. But the mood was clearly tense. Anticipating possible unrest, residents formed long lines at grocery stores and gas stations to stock up on supplies, and armored vehicles with mounted machine guns patrolled the streets, news agencies reported.

Against that backdrop, some international air carriers canceled their flights into the capital, while others were turned back by Nepalese authorities before they could land.

For the past two centuries, Gyanendra's family has dominated Nepal, a country of 25 million people that is as impoverished as it is breathtaking.

The king's action yesterday effectively restored the monarchy to the position of absolute power it occupied before Gyanendra's elder brother, King Birendra, established democracy in 1990.

PAULA BRONSTEIN / GETTY IMAGES Nepalese King Gyanendra, shown at a 2003 gathering, declared an emergency yesterday, firing the government and jailing politicians.

But the monarchy's reputation dived in 2001 when Crown Prince Dipendra killed his father, the popular Birendra, and several other members of the royal family in a palace massacre. He then turned the gun on himself.

Gyanendra was crowned king after the massacre, but has never been as popular as his brother, and is frequently accused of overstepping his powers.

The king had reappointed Deuba in June, two years after firing him for the same reasons he cited this time — inability to tackle the Maoist revolt and failure to call an election.

In January, Deuba had promised to go ahead with the election despite the civil war and the Maoists' refusal to come to peace talks by a Jan. 13 deadline.

But many members of Deuba's cabinet were known to be unhappy with the poll plan on the grounds it was unrealistic in a country where the rebels control much of the countryside.

Gyanendra and his wife will attend a summit of South Asian leaders in Dhaka on Sunday, Bangladesh Foreign Minister M. Morshed Khan said.