Gunmen burst into the Armenian parliament today and opened fire with automatic weapons, killing Prime Minister Vazgen Sarkisian and seven other leading officials before taking hostages and declaring their intent to topple the government, according to witnesses and local media.

The gunmen, captured on a videotape of chamber proceedings, shot the prime minister and then began firing randomly as members of parliament dove to the floor and under their desks. Although the identities of the gunmen could not be immediately confirmed, reports from Yerevan, the Armenian capital, said they were radical Armenian nationalists.

Sarkisian, 40, was taken to a hospital where he died of wounds suffered in the attack, which occurred late in the afternoon while the cabinet was attending a question-and-answer session in the chamber. Also killed were parliament speaker Karen Demirchian; deputy speakers Yuri Bakshian and Ruben Miroian; a government minister, Leonard Petrossian; a senior economic official, Michael Kutanian; and two members of parliament. Although details were still sketchy, Armenian and Russian news agencies said 10 other people were seriously wounded and taken to hospitals.

Troops rushed to the scene, and President Robert Kocharian went to the building tonight to negotiate with the gunmen, who were holding the hostages in a ground-floor cafeteria and demanding time on national television. [Early Thursday, some of the hostages were released, and Kocharian agreed to allow the lead gunman to make a statement on national television, local media reported.]

Accounts from Yerevan said the attackers were issuing pronouncements through the parliament's public address system. One such declaration said that they were carrying out a coup and that seven or eight people must be killed, according to the Armenian news agency Noyan Tapan.

The motive for the attack was not clear, but it coincided with apparently improving prospects for an agreement between Armenia and neighboring Azerbaijan on the disputed region of Nagorno-Karabakh. Armenia won control of the region, an enclave located inside Azerbaijan but populated by ethnic Armenians, and about 20 percent of Azerbaijan's territory in fighting between the two former Soviet republics that ended in 1993.

Officials in Azerbaijan immediately expressed concern that the attack could be an attempt to destabilize Armenia and throw U.S.-sponsored negotiations on the future of Nagorno-Karabakh off track. "I can't exclude that this was initiated by outside forces that want to destabilize the country during the Nagorno-Karabakh talks," First Deputy Foreign Minister Khalaf Khalov told the Reuters news service.

The attack came just hours after Deputy Secretary of State Strobe Talbott left Yerevan following talks with Kocharian on Nagorno-Karabakh. Efforts to settle the conflict have been stalemated for years, and Talbott and other U.S. officials had gone to Armenia after meetings in Azerbaijan as part of an intensified U.S. initiative to bring about a settlement. The Armenian and Azerbaijani presidents have met four times in four months to try to resolve the issue.

There have been reports that a joint Armenian-Azerbaijani statement on the conflict might be signed in Istanbul next month at a summit meeting of the 55-nation Organization for Security and Cooperation in Europe. The OSCE Minsk group--which includes the United States, France and Russia--has been the chief intermediary in the Nagorno-Karabakh negotiations in recent years. U.S. policy is aimed at creating greater economic and political stability in the former Soviet republics along Russia's oil-rich southern rim.

In Yerevan tonight, witnesses identified one of the gunmen as Nairi Unanian, 34, a journalist, while Noyan Tapan identified two others as Unanian's younger brother, Karen, and their uncle, Vram. Nairi Unanian was quoted by witnesses as saying that he is a member of the radical Dashnak Party, a nationalist group that wants Armenia to retain control of Nagorno-Karabakh. But Dashnak issued a statement saying that Unanian has not been a party member since 1990.

Pavel Khachatrian, an aide at the Armenian Interior Ministry, said that five gunmen were involved in the attack, while Armenian television reported there were four.

The television footage of the scene as the gunmen entered the chamber showed a speaker at the rostrum who was identified by Armenian television as Finance Minister Levon Barkhudarian. The gunmen opened fire almost immediately, and legislators scrambled desperately for cover. Legislative aides and others not in the line of fire fled the building in terror, while others were held at gunpoint. One of the attackers could be seen pointing a gun at the lawmakers and shouting, but his voice could not be heard. He then took the rostrum and spoke again, but his words were still inaudible. Later on the tape, the gunmen were seen walking calmly around the chamber, brandishing their weapons. Lilit Belian, a journalist who witnessed the attack, said: "They announced, 'This is a coup d'etat,' and they urged people to come here and seize the building of the national assembly. They said that at last the coup has taken place and someone will be called to account for all that the people had to go through."

Another witness, who was not identified in Armenian television reports, said that Sarkisian was the first person hit when the gunmen opened fire and that he was shot at close range. Sarkisian and Demirchian, the speaker, were political allies and co-chairmen of the Unity party, which holds a majority in parliament. Last year, they pushed for the resignation of President Levon Ter-Petrossian, whom they criticized for agreeing to talk with Azerbaijan about the Nagorno-Karabakh issue.

Sarkisian was appointed prime minister last year by Kocharian, who is a former president of Nagorno-Karabakh. In the late 1980s, Sarkisian was an organizer of the nationalist movement that advocated unity between Armenia and Nagorno-Karabakh, but his more recent political campaign emphasized economic policy. Armenia has been crippled by economic isolation brought about by the dispute over Nagorno-Karabakh.

Background Armenia

Country: About 11,500 square miles, slightly smaller than Maryland.

Population: 3.5 million

Ethnic groups: 93% Armenians; small minorities of Azerbaijanis; Russians and Kurds.

Religion: The majority are Orthodox Christians.

Diaspora: At least 4 million Armenians live abroad, many of whom emigrated during killings of Armenians in 1915 by the Ottoman Empire and in the 1915-1923 Russo-Turkic war. Between 400,000 and 1 million Armenians have emigrated in recent years due to deteriorating economic conditions.

Armenia is one of 15 republics that emerged from the breakup of the Soviet Union in 1991.

Recent Political Events

* Conflict with neighboring Azerbaijan broke out in 1988, when the Armenian-populated enclave of Nagorno-Karabakh, in Azerbaijan, sought greater autonomy. Most people in Azerbaijan are Muslims.

* Nagorno-Karabakh declared independence in 1991, and its militia forces established a corridor connecting it with Armenia. Armenia provided military and political support to the Nagorno-Karabakh Armenians.

* In later skirmishes, Armenian forces widened that corridor and occupied more areas around Nagorno-Karabakh, including towns and villages mostly populated by Azerbaijanis.

* At least 30,000 people have died in the fighting, and nearly

* 1 million, mostly Azerbaijanis, have been displaced.

* A cease-fire agreement was signed in 1994; talks to resolve the status of the enclave have dragged on under the sponsorship of the Organization for Security and Cooperation in Europe, led by the United States, Russia and France.

* Progress was reported recently in the OSCE talks, and some Armenian nationalists com-plained of possible concessions.

Yesterday's attack by Armenian nationalists on parliament

Kocharian

President Robert Kocharian, a native of Nagorno-Karabakh and an independence activist there in the '90s, was directing negotiations with nationalist gunmen who attacked a session of the legislature and took legislators hostage.

Killed

Prime Minister Vazgen Sarkisian; appointed in June after his alliance won a majority in parliament.

Killed

Parliament Speaker Karen Demirchian, a political ally of Sarkisian

Also killed: Deputy parliament speaker Yuri Bakhshian; cabinet minister Leonard Petrosian; senior official Michael Kutanian.

About 10 people were wounded.

SOURCES: Agence France-Presse, Associated Press, Reuters

CAPTION: Police and military personnel barricade the Armenian parliament building, where gunmen held hostages after killing the premier and several officials.