Rangers chief executive Martin Bain was "astounded" by the action after UEFA opened a case against the club over their Europa League second leg against PSV Eindhoven.

The Scottish champions already face action over the first leg in Holland and Bain claimed they appeared to be the victims of a "concerted and deliberate campaign".

Rangers disclosed they had been reported on the basis of a report from the Football Against Racism in Europe organisation rather than the UEFA match delegate, who was from Northern Ireland.

That was also the case with the initial case following the first match seven days earlier on March 10.

An article on the club`s official website revealed that Rangers face "very punitive" consequences if found guilty, including a heavy fine and two-match ban for their home fans.

However, the club have vowed to defend themselves against both charges.

Bain told www.rangersfc.co.uk: "We are absolutely astounded by this latest development and will defend our club's position very, very vigorously.

"We are still in the process of preparing our submission on the away game and to be confronted with this now seems chaotic to say the least.

"We have never said that sectarian singing is not a problem but this now has all the hallmarks of a deliberate and targeted campaign against the club.

"What else are we expected to believe when UEFA officials give us favourable reports at our matches only to indict us later on the evidence of an outside unaccountable body?"

FARE is a Europe-wide organisation started by fans` groups to "fight all discrimination in football".

But Bain argued that Rangers were doing their best to undertake the same cause.

"We could not have done more to eradicate sectarian behaviour," he said.

"We will be seeking urgent meetings with UEFA at the highest level to address these issues.

"It would appear that yet again UEFA have acted on a report from the FARE organisation when their own match delegate, this time from Northern Ireland, gave us a very favourable report."

FARE's website encourages players, fans, professional footballers, clubs and football associations to report alleged abuse and discrimination to them, promising they will then take it up with the relevant authorities.

Rangers have previously been fined for the same offence and UEFA have confirmed that repetition of the same infringement can lead to stricter sanctions.

Rangers received an £8,280 fine on an improper conduct charge for fans' behaviour at an away UEFA Cup game against Osasuna in 2007, the punishment being largely for discriminatory chanting.

They were previously fined £13,300 for supporters' discriminatory chanting and £9,000 following an attack on their opponents' team bus during an away game against Villarreal in 2006.

Rangers were also fined almost £18,000 in November 2009 after their fans clashed with Romanian police during a Champions League match against Unirea Urziceni but avoided sanctions over the trouble that followed the 2008 UEFA Cup final because it took place away from the City of Manchester Stadium.

UEFA revealed last week that the case for the first leg would be heard by their control and disciplinary committee in Nyon on April 28.

Scottish Football Association chief executive Stewart Regan was dismayed by the news.

Regan, who was involved in a recent summit with the Old Firm, Scottish Government and Strathclyde Police officials in a bid to fight sectarianism, told Sky Sports News: "It is very sad for Scottish football that a decision like this has been made.

"Clearly there are commercial implications for the club and nobody likes to see matches played behind closed doors.

"I suppose - having attended the UEFA Congress in Paris a few weeks ago, where Michel Platini made it very clear that UEFA's stance on racism and on sectarianism was going to involve a zero-tolerance approach - that they are carrying out their intention.

"I know Martin Bain and the team at Rangers will be putting forward their case that they are doing all they can to try and stamp out their behaviour, but clearly the fans have let them down on the night."

But Regan added: "Clearly the news is subject to appeal, and Rangers will be appealing on April 20 against this decision."