A mystery bug is giving Celtic a scare before their UEFA Cup match at home to Blackburn on Thursday.

The Scottish Premier League champions meet Blackburn Rovers, who beat English champions Arsenal at the weekend, at their Parkhead stadium fresh from a 4-1 thrashing of Dunfermline yesterday.

However, it emerged after the game that Scotland goalkeeper Robert Douglas and in-form winger Steve Guppy have contracted a mystery bug which could rule them out of the second round, first leg clash.

"Rob felt ill just after training on Friday so the doctor sent him home," Celtic boss Martin O'Neill said.

"On Saturday he was no better and today Steve Guppy was coming with us, but he felt very ill this morning.

"It will be difficult to say at this minute what will happen, but he's no better from Sunday. We will have to see how it is. I just don't know what it is."

The gaping chasm between Celtic and Rangers and the rest of Scotland's top flight clubs was underlined yesterday as the Old Firm notched up 10 goals between them to extend their lead at the top of the table.

Rangers walloped Kilmarnock 6-1 at Ibrox. They continue to head their Glasgow rivals by a single point, but Dunfermline are now 12 points further adrift and any doubt the title race would be a two-horse affair has now been dispelled.

Michael Mols grabbed a brace in the first 15 minutes, Ronald de Boer and Barry Ferguson added two more before Stevie Fulton pulled one back for Killie.

Australian defender Craig Moore made it five and Ferguson rounded off the rout.

Celtic did not have things all their own way at East End Park.

Henrik Larsson scored his 18th of the season and Alan Thompson produced a glorious strike to put Celtic in control.

But Craig Brewster pulled a goal back before Bulgarian international Stilian Petrov and Chris Sutton killed them off.

Hibernian moved up to fourth - and ahead of Edinburgh rivals Hearts - with a win away at Aberdeen.