Russian officials said today that Chechens overwhelmingly approved a new constitution that declares their separatist republic to be a part of Russia.

Preliminary results of Sunday's referendum in Chechnya show that 96 percent of voters approved of the constitution and 80 percent of the electorate turned out at the polls, officials said. President Vladimir Putin said the results demonstrate that the rebels who have battled the Russian military on and off since 1994 are fighting "against their own people."

"We have resolved the last serious problem related to Russia's territorial integrity," he declared in nationally televised remarks.

Critics said the referendum was a sham because it essentially offered Chechens the choice of capitulation to Russia or more war. Human rights activists said no democratic results could be obtained given the atmosphere of intimidation and fear in the republic, where 80,000 Russian troops are present.

But Kremlin officials pronounced the referendum a resounding success and said it was a sign that normal life was slowly taking hold in the republic after two wars with Russia in the past decade. Putin's aides promised that presidential and parliamentary elections would be held in the Chechen republic later this year and that amnesty would be granted to 2,500 rebels who have surrendered over the past 31/2 years.

Viktor Kazantsev, Putin's envoy to the southern Caucasus region that includes Chechnya, said 500 militants had already been amnestied.

Many Chechens who opposed the referendum chose to stay home rather than vote. The most negative votes were recorded in the mountainous villages in southern Chechnya, where sympathy for the rebels is strongest. Abdul Arsakhanov, head of the Chechen election commission, said no district recorded higher than a 9 percent vote against the constitution.

The voting took place under heavy security. In the days leading up to the referendum, shots were fired at 18 of 418 polling places, Arsakhanov said. One local election official was killed, although Arsakhanov said he believed her death was unrelated to the vote.

Turnout was apparently low in the refugee camps in the neighboring republic of Ingushetia, where about 30,000 Chechens remain camped out in tents. Some have been there for 31/2 years. Arsakhanov said only 5,000 refugees voted.

Between 27,000 and 36,000 Russian soldiers who are permanently assigned to Chechnya were eligible to vote. Although election officials insisted the soldiers were a tiny portion of the more than a half-million eligible voters, their participation disturbed many Chechens.

A Russian soldier stands in front of a portrait of Russian President Vladimir Putin in Grozny, capital of the war-torn republic of Chechnya.