FACTBOX | Top US general outlines initial timeline of US military operation in Iran

Top US General Dan Caine, Chairman of the Joint Chiefs of Staff, on Monday gave an initial timeline and some details on the start of the US military operation in Iran. So far four US service members have been killed and four others remain seriously wounded, the military has said.

February 27:

At 15:38 ET (20:38 GMT), the US Central Command received "the final go order" from President Donald Trump: "Operation Epic Fury is approved. No aborts. Good luck."

US forces made final preparations: Air defense batteries checked systems to respond to Iranian attacks; pilots and crews rehearsed strike packages for the final time; air crews began loading final weapons, two carrier strike groups began to move toward launching points.

The first moves were made by US Cyber Command and US Space Command, which worked to disrupt, degrade and blind Iran's ability to see, communicate and respond before the attack began.