CAIRO, Egypt (AP) _ Army troops called out to suppress a mutiny by paramilitary forces today opened fire with machine guns, tank cannon and automatic rifles on a rebel camp beneath the Great Pyramids, witnesses said.

The Central Security Force uprising began Tuesday night after rumors spread that the term of involuntary service of the conscripts would be extended from three to four years. Instead, it was cut by one month.

Despite today's clash, President Hosni Mubarak's chief political adviser, Osama el-Baz, said security had been restored after the most serious domestic unrest of Mubarak's four-year tenure.

El-Baz told reporters 36 people were killed and 321 injured in the mutiny and riots that followed.

He said the dead were 32 members of the security forces, two army soldiers and two civilians. He said 273 of the wounded were members of the paramilitary security forces, 12 were soldiers and 36 were civilians.

The shooting today broke out around the pyramids at about noon, according to witnesses. Associated Press photographer Paola Crociani, who reached the area an hour later, said the shooting had stopped but army officers were nervous and ordered reporters from the area.

A curfew ordered Wednesday to control the disturbances was suspended for three hours today to allow Cairo's 12 million people buy food and essential supplies. Food shops throughout the capital were jammed.

Soldiers in battle dress patrolled Cairo's largely deserted streets in tanks, armored personnel carriers and armored cars. White-helmeted military police manned roadblocks at key intersections in the heart of the city.

The city was reported generally quiet, but residents of at least three neighborhoods reported hearing sporadic shooting.

Western diplomats, speaking on condition they not be identified, said gangs of renegade troops exchanged gunfire before dawn with army troops in the Shubra District of northern Cairo.

Residents of the mixed Moslem-Christian neighborhood, reached by telephone, confirmed hearing heavy bursts of automatic fire overnight.

Armored personnel carriers blocked roads leading into parts of Shubra early today, and soldiers prevented reporters from entering the worst hit areas.

Residents of the southern suburb of Maadi, where many American and other foreign diplomats live, reported hearing sporadic gunfire through the night to the east of Tourah Prison, which mutinous security troops stormed Wednesday to release prisoners, including Islamic extremists.

Rioters burned three luxury hotels and several nightclubs near the Great Pyramids, attacked cars and police stations, and stormed the prison.

Three French citizens were injured while trying to escape a fire at the Swiss-owned Jolie Ville Hotel, according to a French Embassy source who spoke on condition of anonymity.

EgyptAir, the national carrier, announced plans to evacuate about 700 foreign tourists by special charter flights to Europe today.

U.S. Embassy spokesman Ed Bernier said about 120 Americans were staying in hotels near the fighting, but none was reported injured. He described the Americans as ''stunned, shaken and fearful.''

Cairo's leading newspaper, government-owned Al-Ahram, said the army had sealed off most security forces camps around the capital and was searching for some mutineers who managed to escape.

Mubarak, in a nationally broadcast speech Wednesday, blamed the unrest on ''deviationist elements'' and said an undisclosed number of guards at hotels, nightclubs and shops in the riot area had been slain by mobs.

The rioting was the worst outbreak of violence in Cairo since the 1977 riots against food price increases, and presented Mubarak with his most serious domestic challenge since he took office in 1981 after the assassination of President Anwar Sadat.

Mubarak said ''large numbers'' of the mutineers had been arrested, and clashes also had taken place in the cities of Assiut, Sohag and Ismailia as well as in rural garrisons near Cairo.

However, Information Minister Safway el-Sherif denied there had been trouble in Ismailia and said Mubarak was referring to clashes at a camp on the Cairo-Ismailia highway near the capital.

The largely conscript Central Security Force, which numbers 120,000, is responsible for guarding embassies and key government and military installations and curbing street demonstrations.

Thousands of the conscripts, angered by rumors their enlistments were being extended, stormed out of a garrison Tuesday night in the shadow of the Great Pyramids and went on a rampage.

They were joined by hundreds of civilians angry over price increases and shortages brought on by the country's rapidly deteriorating economy.

Enlisted members of the force, most of whom come from poor peasant families, earn the equivalent of $3 to $4 a month and receive few benefits beyond free clothing, food and housing - tents in desert camps.