Security police conscripts went on a rampage on the outskirts of Cairo and several other cities last night and early today, and at least 15 persons were killed, scores wounded and two luxury hotels near the Pyramids burned down before Army troops restored order.

Soldiers in tanks and armored personnel carriers patrolled this vast capital and other cities, and the government declared an indefinite curfew effective at 4 p.m.

Witnesses said the rioters set cars on fire in the wealthy Cairo suburb of Maadi, where many foreigners live. There were no reports of foreigners injured or killed, and the overall number of casualties remains unknown.

The crisis is the most serious since President Hosni Mubarak took office after the assassination of president Anwar Sadat by Moslem extremist soldiers in 1981. The riots come at a time of deepening economic crisis in Egypt, and will make it more difficult for Mubarak to make the tough economic decisions that the country's financial backers have been pressing him for.

The rioting began near the Pyramids at Giza at about 10 last night, when police conscripts went on a rampage in four training camps around the city, apparently in response to rumors that their three-year terms of duty would be extended by a year. The police rioters, whose numbers were estimated at 8,000 by one unofficial source, were joined by young civilians, said to be angry over recent price increases.

Government spokesmen called the rumors "groundless," and one source said the government actually had decided to cut the police conscripts' terms by a month to save money.

The United States, which provides about $2 billion a year in aid, has been pressing Egypt to make deep cuts in its massive subsidies of prices of consumer products, viewed here as politically necessary to avert an uprising by the potentially volatile underclass.

The security police who mutinied overnight are drafted from the poorest sectors of society and are paid the equivalent of about $4 a month and two meals a day. The riots, directed at symbols of luxury, appear to reflect a deepening sense of deprivation, according to observers here.

In a televised statement tonight, Mubarak described the events as "a treacherous blow" to Egypt's efforts toward economic development. He blamed the rioting on "saboteurs" who "incited" the police at the camps, and said that the state prosecutor will investigate the case.

Police said rioters stormed the Tura prison south of Cairo, where many Moslem fundamentalist and other political prisoners are held, and freed most of the convicts. In Asyut, a fundamentalist stronghold on the Nile River about 200 miles south of Cairo, mutinying police reportedly waged a gunbattle with Army troops before being driven back to a camp outside the town.

Mubarak said that police and soldiers also fought in Ismailia, on the Suez Canal, and in the southern Nile city of Sohag. An Interior Ministry spokesman said rioters set fire to a train in the Cairo suburb of Helwan.

Last month, students demonstrated in Cairo over the prison death of police conscript Suleiman Khater, who was convicted of killing seven Israeli tourists in the Sinai.

Similar uprisings took place in 1977, when Sadat tried to raise the prices of bread and several other subsidized foods.

At 4 this afternoon, when the curfew was supposed to go into effect, rioters were still burning nightclubs on the road leading to the Pyramids at Giza. Black plumes of smoke billowed from the windows of one nightclub, and bonfires roared in the street.

Earlier in the day, ambulances were seen racing back and forth from the area of the Pyramids, where the conscripts had battled with soldiers during the night. The Jolie Ville hotel and the Sphinx Holiday Inn were completely burned out, and the Pyramids Holiday Inn was badly damaged by fire.

At least 600 foreign tourists at the hotels were safely transferred to other locations, officials said.

A British couple at the Mena House Hotel, also in view of the Pyramids, said they heard gunfire and "the mobs chanting" in the streets until about 5 a.m. The rioters briefly entered the Mena House, but did only minimal damage to the lobby.

"They walked into the lobby with bottles, half-drunk, with guns in their hands," said Adel Abdel Hai, food and beverage manager at the Mena House. He added, "But they were not harming people. They didn't even talk to us."

One western diplomat who was near the burning hotels last night described the scene as "completely out of control." Fire trucks were unable to reach the hotels because of the fighting, the diplomat said.

Dozens of tanks and armored personnel carriers were stationed this afternoon at the Pyramids area, which looked like a war zone, littered with burned-out cars, broken glass and other debris.

In suburban Maadi, where another police training camp is located, gun battles were heard much of the day. An Associated Press reporter saw one dead body in the street, and there have been unconfirmed reports of other deaths there.

Rioting also took place at a police camp near the Cairo International Airport. The airport was closed beginning at 7:30 this morning. Some reports indicated that air traffic had resumed by late afternoon, but it was not clear if this applied to incoming as well as outgoing flights.