Undated (AP) _ Key dates in Russia's struggle with separatists in Chechnya:

1991

-Sept. 6 - Dzhokhar Dudayev, retired Soviet air force general, leads ouster of Chechnya's Soviet government with tacit approval of Russian authorities.

-Oct. 27 - Dudayev elected president.

-Nov. 1 - Dudayev declares Chechnya independent.

-Nov. 2 - Russian parliament calls Dudayev's election illegal.

-Nov. 7 - Russian President Boris Yeltsin announces emergency rule in Chechnya.

-Nov. 9 - About 1,000 Soviet Interior Ministry troops fly to Grozny and approach capital. Tens of thousands of Chechens block the streets and airport.

-Nov. 10 - Soviet troops retreat.

1992

-Oct. 11 - Dudayev declares state of emergency after thousands of Russian troops mass on border.

-Nov. 18 - Troops from both sides pull back.

1993

-April 2 - Dudayev dissolves parliament, declares one-man rule.

-June 5 - Dudayev calls out tanks to halt referendum on one-man rule. Thousands protest against him.

1994

-June 13 - Fighting between pro- and anti-Dudayev forces breaks out in Grozny.

-Aug. 2 - Russia openly supports the opposition, although Yeltsin rules out use of force.

-Nov. 25 - Helicopter gunships attack government positions near Grozny. Officials say airships had Russian markings; Moscow says military uninvolved.

-Nov. 26 - Opposition retreats after fierce fighting at presidential palace.

-Nov. 28 - Chechen authorities threaten to execute about 70 Russians captured in fighting. Dudayev later says they'll be tried in court.

-Nov. 29 - Yeltsin orders Chechens to lay down arms by Dec. 1 or face Russian intervention. Unmarked Russian jets bomb Grozny.

-Dec. 1 - Yeltsin deadline expires, Moscow backs off threat to send troops.

-Dec. 6 - Russian Defense Minister Pavel Grachev meets with Dudayev. Dudayev promises to release Russian troops taken prisoner.

-Dec. 8 - Chechnya frees last Russian servicemen held.

-Dec. 9 - Yeltsin authorizes use of force.

-Dec. 11 - Russian tanks roll into Chechnya, 10,000 to 40,000 Russian soldiers are backed by jets and helicopter gunships. Chechnya agrees to talks.

-Dec. 13 - Russian aircraft blast Chechen positions after talks fail.

-Dec. 14 - Chechnya suspends talks. Russian artillery pounds village north of Grozny.

-Dec. 15 - Yeltsin extends deadline to lay down arms by 48 hours. Russian army moves closer to Grozny.

-Dec. 16 - Dudayev pulls fighters back to Grozny but sticks to demand that Russian troops leave. Russian column halts advance when villagers block a road; Russian general says his soldiers won't fire on civilians.

-Dec. 18 - Efforts to restart talks fail. Russian planes bomb outskirts of Grozny and troops advance toward city.

-Dec. 20 - Chechnya says 120 people killed in overnight air raids on Grozny. Hundreds of thousands line the roads to protest Russia's offensive.

-Dec. 22 - Waves of jets attack Grozny with bombs, killing at least 24. Dudayev calls for an Islamic holy war against Russia.

-Dec. 23 - Russian jets and helicopter gunships pound burning Grozny. Residents try to flee. Russia says 44 of its troops killed so far in Chechnya.