Russian bombs and artillery rained down on the Chechen capital with renewed intensity today, setting an oil depot ablaze and sending black smoke spewing into the sky.

Both sides claimed to be inflicting heavy casualties in the protracted fight for Grozny. Russian soldiers pounded the city with mortar fire, and heavy fighting was reported at a meat canning factory and in other parts of the city.

The oil depot at Grozny's main refinery caught fire after it was bombed by Russian warplanes. Chechen rebels said one of their antiaircraft units shot down an Su-25 bomber in Grozny on Friday night. The Russian Defense Ministry denied the claim today.

Russia's acting president, Vladimir Putin, insisted the offensive was going according to plan, despite rebel attacks last week that set back the Russian campaign.

"We'll take Grozny . . . and then we'll finish the operation in the mountains," he said on ORT television tonight.

Lt. Col. Konstantin Kukharenko, a military spokesman, said Russian troops had captured the towns of Sharoi and Simoi in the south.

Isa Munayev, the rebel commander in Grozny, said 28 Russian scouts were killed today in the capital. Russia said it killed 58 rebels, the official Russian Tass news agency reported. But the casualty claims cannot be verified.

Also today, the president of the neighboring Russian region of Ingushetia said the military had lifted all restrictions on Chechens trying to enter or exit Chechnya. The Russian order last week to detain all males between 10 and 60 to check for rebel ties provoked international criticism.