GROZNY, Chechnya -- Chechen forces claimed to have executed a Russian air force pilot Tuesday for carrying out bombing raids in the breakaway republic, Interfax said.


The chief of Chechnya's information service, Movladi Udugov, was cited as saying Nikolai Bairov had been sentenced to death for bombing the Chechen town of Shali.


The Russian military could not immediately be reached for comment. The report did not specify how or when the pilot had been captured or sentenced.


Udugov said the commanders of two Russian air force units also had been sentenced to death in absentia for ordering airstrikes on residential areas, according to Interfax.


Shali is located 25 kilometers southeast of Grozny.


It is one of the remaining strongholds of fighters loyal to Chechen President Dzhokhar Dudayev. It has been a frequent target of Russian warplanes.


Russian troops moved Tuesday to encircle the city of Argun, a key stronghold of rebel Chechen fighters some 25 kilometers west of Grozny, the government's press service said.


It said Russian troops crossed the River Argun, took an important hill, a railroad and a road leading to the city from the west.


"Artillery and aviation of the federal troops are delivering strikes against groups of militants," the service said.


Russian planes and artillery dealt powerful strikes Monday night and Tuesday on Shali as well as Argun, Gudermes and several other villages east and southeast of Grozny, Itar-Tass said.


Monday marked the 100th day of the war. Russian troops entered the secessionist region in the Caucasus Mountains on Dec. 11 in an attempt to crush its three-year independence drive and restore Kremlin control.


(AP, Reuters)