Rangers have issued a warning to all fans attending Sunday's Viaplay Cup semi-final that they 'risk arrest' if they possess or use pyrotechnics.

Philippe Clement's side will take on Hearts at Hampden for a place in the final of the competition. They will meet either Hibernian or Aberdeen who play on Saturday evening.

The use of pyro by supporters inside football grounds has come under an intense spotlight this week after the entire away end at Dens Park was illuminated red on Wednesday night by some of the Rangers faithful, believed to be the Union Bears.

A large amount of flares were set off as the Dundee and Rangers players were forced off the pitch after just two minutes, which caused further delays to the fixture.

The Scottish FA and SPFL have joined forces to urge supporters of all four teams heading to the national stadium in Glasgow this weekend to enjoy themselves and refrain from using pyro. 

Now, Rangers have also sent out a similar warning to their fans, reminding them that the use of pyro at matches is illegal in Scotland. 

An email has been sent out by the club detailing important information ahead of Sunday's showdown. It reads: "Supporters are reminded the use of pyrotechnics is illegal within Scottish football stadiums, and any supporter found to be in possession of a pyrotechnic device at any match risks arrest. The club can also be sanctioned for any use of pyrotechnics within a stadium."

It's understood that every Rangers supporter with tickets will receive the email directly.

Wednesday night's incident at Dens is under investigation by Dundee, who condemned those who set off the fire alarm at the stadium as a result of their actions. 

READ MORE: SFA & SPFL issue joint Hampden pyro warning after Rangers fans' flares

A joint SFA & SPFL statement reads: "Ahead of this weekend’s Viaplay Cup semi-finals at Hampden Park, the Scottish FA and Scottish Professional Football League call on supporters to enjoy the showpiece occasions in a safe and responsible manner.

"Given the increased focus on the use of pyrotechnics, we appeal to fans of all four participating clubs to enjoy the matchday experience at the National Stadium but to do so in a manner that does not endanger the safety of their fellow supporters, or that has the potential to disrupt the matches themselves.

"The use of pyrotechnics is illegal. That message has been reiterated in the strongest possible terms by the police and football safety authorities, and reinforced by the SPFL and Scottish FA, during operational meetings with the participating clubs this week. 

"The safety, security and enjoyment of tens of thousands of fans who will fill the National Stadium this weekend is paramount and there will be a range of steps put in place to help identify anyone who transgresses, including additional security measures and CCTV surveillance.

"We ask for your help in ensuring the weekend action is memorable for the excitement and entertainment generated on the field and not for any unwanted behaviour off it."