* Major air war has begun against Iraq, U.S. official says

* Large blasts detonated to west of Baghdad after air raid sirens sound and anti-aircraft guns open up; air strikes on northern city of Mosul, Al Jazeera TV says

* British Defense Chief Boyce cannot confirm report Saddam likely killed in first Baghdad air strike

* U.S. armored columns advance toward Baghdad; one unit runs into resistance from Iraqi troops near Nassiriya, a main crossing over Euphrates river

* Iraq vows to "incinerate" invaders, says Saddam survived missile strike

* U.S. troops seize two airfields in western Iraqi; British defense source says main aim tonight is to take Basra

-- QUOTES

British defense chief Boyce on report Saddam likely dead: "No I can't confirm that... I'm certainly unaware of Saddam Hussein's status at the moment."

-- EVENTS

Friday --

* Possible Rumsfeld briefing (1830)

* Schroeder speech on war (1940)

Saturday --

* Iraqi opposition leaders meet to discuss post-war political role

* Anti-war protests in London, Paris, Stockholm

Monday --

* Arab foreign ministers' meeting in Cairo