Chechen Fighters Launch Attacks on Russian Troops : Caucasus: Kremlin says rebels are preparing major action in bid to embarrass Moscow during WWII commemoration.

Chechen fighters Tuesday stepped up hit-and-run attacks on Russian troops, who officials say are bracing themselves for a rebel offensive when President Boris N. Yeltsin meets world leaders next week.

The Russian Interior Ministry press center in Grozny said separatist leader Dzhokar M. Dudayev had declared a May 9 “Night of the Long Knives.” Yeltsin is scheduled on that date to host dozens of world leaders in Moscow during Victory Day celebrations to mark the 50th anniversary of the end of World War II in Europe.

The report of rebel plans could not be independently confirmed, but new Chechen assaults suggested more fighting is in store.

Three Russian troops were killed and eight injured Monday night when Chechen rebels attacked a convoy approaching Grozny, the breakaway republic’s capital, the Itar-Tass news agency reported.

Itar-Tass also reported persistent fighting overnight within Grozny, including an attack on the military commandant’s office.

Army commander Maj. Gen. Gennady Toshev told Itar-Tass that he believed that most rebels viewed a moratorium on fighting declared by Yeltsin four days earlier as a “farce.”

The rebels used mortars and grenade launchers as well as light weapons, he said.

A Russian Defense Ministry spokesman in Khankala, four miles east of Grozny, said four Russian soldiers had died and 13 had been injured in Chechen attacks since Monday.

Russia sent its top security chief to Chechnya on Tuesday in a bid to restore order as the resurgent fighting shattered weeks of relative calm in Grozny.

Sergei V. Stepashin, director of the Federal Counterintelligence Service, a successor to the Soviet KGB, told Interfax news agency that he was visiting Chechnya to help bolster and expand security.

Stepashin, who met later with leaders of the Chechen provisional government, said it is crucial to disarm rebel militias and stop raids on federal troops.

He was also quoted as saying one priority is to secure the region’s petroleum production plant so that it can start working again.

His visit underscores the Kremlin’s impatience to mop up rebel resistance in Chechnya and its anxiety about renewed fighting in Grozny just a week before the May 9 celebrations.

Renewed bloodshed in Chechnya could cause Yeltsin serious political embarrassment in front of foreign dignitaries. Among the official guests will be President Clinton, who will hold a summit with Yeltsin on May 10 and 11.

Dudayev, with a clear interest in bringing the conflict to the world’s attention next week, has ignored the cease-fire.