Martin O'Neill has admitted that he was at Celtic's friendly match with Chelsea on Tuesday night, where Aston Villa target Stilian Petrov did not make an appearance for the Glasgow side.

But the events which followed probably made him wish he had stayed in Holland with the Villa team who are currently on pre-season tour.

O'Neill denied that any talks took place regarding Petrov's future despite the fact that he is believed to be the new manager's number one target for the new season.

He said his attendance at Stamford Bridge had been arranged weeks earlier, before he became Villa manager.

But it seems highly likely that Petrov will sign for Villa before the transfer deadline at the end of the month with a £5 million fee likely to be spent on the Bulgaria midfielder.

However, O'Neill's attempts to head back to England to rejoin Villa at their Dutch training camp were heavily delayed by the security alert at Heathrow Airport.

O'Neill was caught up in the chaos as he attempted to board the 8.40am flight to Amsterdam.

"It was absolute bedlam," said O'Neill, who arrived back in Holland around four hours later than first planned.

But O'Neill returned to suggestions that his visit to London to see former club Celtic had been significant considering the links with Petrov.

Celtic manager Gordon Strachan said that no-one would be leaving the club until he had strengthened his squad first, although former Birmingham City loanee Jiri Jarosik is being seen as a replacement for Petrov.

O'Neill had also been spotted talking to Celtic officials at Stamford Bridge, again sparking talk that a move for Petrov was imminent. But now it seems unlikely that Petrov will be signed in time for tonight's final game of Villa's tour against FC Groningen.

"I wouldn't be denying that I was at Chelsea but that was just one of the reasons why I had to go back," said O'Neill.

"And I was speaking to the chairman and chief executive, but I hadn't seen them for a long time and I didn't discuss any transfer moves with them.

"Naturally, I'm trying to strengthen the squad as far as I can between now and the end of August which isn't long. At this minute, there's nothing imminent and there's no chance of anything before we get back to England.

"On Wednesday night, I had been invited to the game some weeks ago, before I was manager of Aston Villa.

"It wasn't an appropriate moment to be talking football business, there were a number of other people and conversations going on. It wasn't somewhere where you'd pull someone to one side for a talk."

But O'Neill admitted that he did not suspect that his travel problems in trying to get back to Holland were as serious as they were.

The Villa manager thought he would be able to get back eventually, but was shocked at the scale of the security alert. "I never thought that it was going to be as big a problem as it has obviously turned out to be," said O'Neill.

"Only for a moment or two did I think I wouldn't make it back. I felt it would be late evening when I finally arrived.

"When I got to the top of the queue and was told the plane was finally leaving, then for the first time I thought I'd be OK."

O'Neill is likely to try out a number of combinations once more tonight against Groningen to try and figure out his best side before the start of the Premiership season.

The manager gave new roles to Jlloyd Samuel and Luke Moore in Nijmegen in Tuesday's friendly and rearranged his formation finishing with three strikers up-front.