NAZRAN, Russia, 2 August 2003 — A truck packed with explosives blew up outside a hospital at a Russian military base in a region bordering rebellious Chechnya yesterday, destroying the building and killing at least 35 people, officials said.

At least 35 people were killed, Russia’s deputy prosecutor general said. The bodies of 35 people were recovered from the shattered building, Sergei Fridinsky told the Interfax news agency, warning that the toll was almost sure to rise.

“Judging by the scale of the destruction and the number of people who were in the hospital — 150 people, including 100 patients and 50 staff members — the number of casualties will probably be much higher,” Fridinsky said at the site of the attack.

Russian military headquarters in the region said 135 people — patients and medical staff — were in the hospital when the truck exploded at 7 p.m. local time, collapsing the building in a wall of flames, according to Interfax news agency.

“At least 35 people have been killed, the building is burning and it is impossible to approach it. All four stories have collapsed,” a spokesman for the local branch of Russia’s Emergencies Ministry said.

The attack took place at Russia’s army base of Mozdok in the region of North Ossetia bordering Chechnya.

Chechnya, in the grip of a 10-year separatist insurgency, is gearing up for an Oct. 5 election to choose a regional president — a key event in President Vladimir Putin’s plan to restore peace to the area. Putin ordered Defense Minister Sergei Ivanov to fly to the scene of the attack, the Kremlin said.

Interfax quoted an official at the hospital as saying rescue teams had dragged 35 bodies from under the rubble. Troops had cordoned off the area but rescue work was hampered by fire which has consumed the wrecked building.

Itar-Tass news agency quoted officials in Mozdok as saying 22 people wounded in the attack had been taken to hospital, two of them in serious condition.

Earlier, battles between Chechen separatists and Russian troops broke out across the breakaway southern republic yesterday, leaving at least four federal soldiers, three pro-Russian Chechen policemen and 17 rebels dead, news agencies reported.

Rebels attacked a vehicle carrying Russian troops through the southeastern region of Vedeno, killing two Interior Ministry soldiers and two special agents with the Federal Security Service (ex-KGB), a police source told RIA Novosti. The 17 rebels were killed in a series of raids.