George Clooney launched a verbal tirade against a security guard at the London premiere of his latest movie last night (3NOV05).

The actor was in England's capital to attend the star-studded screening of GOOD NIGHT GOOD LUCK, when his attempt to leave quietly at the end of the event was hampered by vehicle confusion.

Clooney and ex-girlfriend LISA SNOWDON left the West End club through a side exit where a car had been scheduled to meet them.

But a mix-up left the couple stranded in the back alley with a nonplussed security guard.

An onlooker told British newspaper The Evening Standard, "The security guard was walking down the alley and George screamed at him, 'Come back here' and then he said 'I am going to f**king have you!'"

Clooney reportedly chased the guard, despite former TV presenter Snowdon's best attempts to diffuse the situation.

The source adds, "He squared up at the security guard and Lisa was screaming at him, 'George, George come here.' She grabbed his hand and tried to pull him away and finally a Jeep pulled up.

"I was genuinely shocked. I just couldn't believe what I was seeing.

"You just don't expect George Clooney to start a fight with a security guard."