HEARTS warned yesterday that security will be tightened at their Bank of Scotland Premierleague match against Celtic on Sunday, amid fears that hostility between the two sets of supporters could lead to crowd trouble.

Security chiefs are preparing for possible trouble because it is believed some Celtic supporters have bought tickets for parts of Tynecastle usually occupied by Hearts fans in anticipation of the Glasgow team winning the league title there.

Hostility between the two sets of fans was heightened on April 10 when Hearts supporters booed a minute's silence in honour of the late Pope before the Tennent's Scottish Cup semi-final between the teams.

Celtic fans have received their usual official allocation of 3000 tickets for the away section of Tynecastle. However, some fans apparently bought tickets for the Hearts sections of the ground several weeks ago when Celtic's lead in the Premierleague meant it was likely that a win at Tynecastle in the penultimate round of matches would secure the title.

A surprise Hibernian victory at Celtic Park on April 30 increased the chances of the title race going to the last round of matches on Sunday week - when Celtic travel to Motherwell and Rangers to Hibs - although Celtic could still win the league at Tynecastle if Rangers fail to beat Motherwell on Saturday.

The bad blood between Celtic and Hearts fans was increased again two weeks ago when the Edinburgh club said that if Celtic did secure the league title at Tynecastle, they did not want them to receive the championship trophy there for security reasons.

Security staff at Hearts are also aware of the possibility of trouble among the home fans on Sunday following the ousting this week of John Robertson, the Tynecastle club's former head coach.

There were reports yesterday that some Hearts fans were planning a demonstration against Chris Robinson, the controversial club director, and his role in the departure of Robertson, a former playerwho is revered among the Tynecastle fans.

Gary Mackay, the man who has played more games for the Tynecastle club than anybody else, has called for a protest against Robinson at the match and has demanded his immediate removal from the club.

A Hearts spokesman said last night that security at the match would be tight and anybody found in the wrong end of the ground would be ejected.

He said Hearts were working closely with Celtic, the police and the stewards to identify any Celtic fans who had bought tickets for the wrong sections of the ground.

ALothian and Borders Police spokeswoman said they were confident they could cope with any possible f lashpoints.

She added: "We have heard about the possibility of a demonstration by the home supporters and as long as it remains within the law it be allowed to take place."

Meanwhile, Motherwell will today put tickets on sale for the final day match against Celtic on May 21, amid fears that Celtic fans are also set to infiltrate home sections of Fir Park.

John Boyle, the Motherwell chairman, previously suggested that home fans with season tickets for the Davie Cooper Stand should switch their seat for one day and allow the club to sell tickets for that section to Celtic fans, but Fir Park regulars rejected the proposal.

A Motherwell spokesman said: "There's just under 3000 tickets due to go on sale and they're aimed primarily at Motherwell supporters.

"There is no point in Celtic fans buying tickets for these areas, it is a pointless exercise.

If supporters are identified as being Celtic fans in these areas then they will be ejected from the stadium on public safety grounds. The stewards and police have assured us that the stewarding will be robust and every precaution possible will be taken."