A military spokesman said today that Russian forces were responsible for the bombing of a market in Grozny, the capital of Chechnya, that killed scores of people on Thursday. But the official said the market was an arms bazaar and that the victims were merchants selling weapons to the region's separatist guerrillas.

Other Russian officials, including Prime Minister Vladimir Putin, said Russian forces had nothing to do with the blasts, which tore through the crowded market and also damaged a maternity hospital.

Putin's statement distancing the government from the attacks -- on a day of confused and contradictory statements -- came as concern grew in Moscow and abroad about the mounting civilian casualties in Chechnya during a three-week-old Russian ground offensive against separatist Islamic militants in the breakaway southern region.

Despite the confusion in the Russian government, reports from Grozny said the rocket salvos that hit the city were the type that Russian forces have used to bombard the capital and other towns and hamlets during the offensive. Reporters in Grozny observed shell casings from rockets strewn about the destroyed stalls of the marketplace.

Russian troops, who have advanced to within seven miles of Grozny, shelled the city's northern suburbs today, the Interfax news agency said. Military officials said the army planned to surround the city, which was devastated during a two-year war that ended in 1996 with a Russian withdrawal and Chechnya's effective independence.

The death toll from Thursday's market attack topped 140, according to reports from Grozny. Reuters news service correspondents counted 30 bodies at a hospital and another 60 at the entrance to the market, the site of open air cafes and food stalls. They said teenagers and children were among the dead. Television pictures broadcast in Moscow showed a jumble of tin roofs and wooden supports in the flattened square.

Russian officials were tongue-tied for much of the day today, and their explanations changed almost hourly. The government has insisted that its forces are not attacking civilians, though the death toll among Chechens from the ground fighting runs into the hundreds. Russian officials fear that the mounting toll of civilian casualties could lead to an increase in foreign sympathy for the Chechens, whom they have worked hard to label as terrorists and criminals.

Col. Alexander Veklich, an army spokesman in the north Caucasus war zone, said a "special operation" was carried out at the market, which he said doubles as an arms bazaar. "As a result of the special operation, the market, together with weapons, ammunition and arms traders, were eliminated," he said. Veklich said neither aircraft nor artillery was used, but declined to explain what caused the carnage.

"The operation was conducted by non-army methods," he said.

The market is partly an arms bazaar. Next to stalls selling tomatoes and bread, militia groups sometimes line up to haggle over AK-47 rifles and machine guns.

Veklich said that civilians do not visit the market in the evening, which was when the attack occurred. "If there were any casualties, they were those who sell weapons to bandits and terrorists," he said.

On recent visits to Grozny, however, reporters observed numerous markets open at night, illuminated only by candlelight and kerosene lamps.

The attack came at an inopportune moment for Putin, who launched the ground offensive in late September in response to Chechen guerrilla assaults on the neighboring region of Dagestan and a series of apartment building bombings that killed more than 300 people and that Russia blamed on the guerrillas.

Putin attended a European Union summit in Helsinki today, where European leaders expressed alarm at the mounting violence in Chechnya and called for negotiations.

Putin said the marketplace explosions were caused by a battle between Chechen guerrillas. He also spoke of an unspecified special operation by Russian forces, but said it was not aimed at the market. Nonetheless, Putin took pains to label the market as a legitimate military target. "This is a weapons base. This is a place where bandits concentrate," he told reporters in the Finnish capital.

Nikolai Patrushev, director of the Federal Security Service, the Russian successor to the KGB, added to the confusion by saying he knew nothing of a special operation. The Russian Information Center, which Putin created to release official accounts of the war, accused Chechen field commanders of carrying out the bombings to discredit Russia.

The Russian television station NTV suggested that the likely projectile used to hit the market was the Tochka, a short-range Russian surface-to-surface ballistic missile designed to carry conventional and nuclear warheads.

It remained unclear whether Russian forces intended to lay siege to Grozny. Russian troops command strategic heights north and west of the city. Russian forces also crossed the eastern section of the Terek River, about 20 miles from Grozny. Until a few days ago, the Russian military had stopped its advance at the river's northern bank.

In another development, Moscow police late Wednesday arrested Mairbek Vachagayev, the head of Chechnya's representative office here, effectively crippling one of the region's main links to the outside world. Police said Vachagayev and an assistant, Musa Nugayev, were illegally carring two pistols.

Vladimir Kozlov, a police official, said Russia would consider an offer to trade Vachagayev for Gen. Gennady Shpigun, a Russian official kidnapped in Chechnya earlier this year.