Sisters Mie, 22, and Mille Debray, 24, make up group The Soap Girls and have been touring England the last few months.
But the pair say they were left horrified after buckets of fake blood were thrown over them mid-song during a set at The Union Bar in Hastings.
The young South African sisters said the sticky red glue-like substance ended up in their eyes after it was hurled over their faces.
The pair powered through and managed to finish their set but say they have both been left emotionally scarred since the incident and have since sought legal action.
Mie, who often takes to the stage topless, said: “We were performing the third song and as I looked up I remember this excruciating pain in my eyes and I couldn’t see at all.
“I was absolutely covered in this sticky red stuff and when I looked at my sister she had it all over the lower half of her body.
“The people who threw it at me came back and hurled more all over my gear and everything was covered.
“Then they stood at the end of the room smirking at us and heckling us, it was horrible but we didn’t stop. When the attack happened I felt so low.”
Older sister Mille said she didn’t know what had happened but her fingers were slipping when she was trying to play her bass and looked down to see the liquid.
She added: “When I looked at my sister she turned around and her eyes had gone red it was so scary.
“I didn’t know what was going to happen next but I was scared I was going to get electrocuted because of the liquid all over my guitar.
“There is no justification for this, it was wrong and they haven’t even apologised. There is no excuse for it.
“Our message is freedom. We are all about female empowerment and doing what you were born to do, we shouldn’t have to be told what to do.”
The sisters had travelled six hours from Grimsby to do the gig after they were booked by Mr Osmond for £50 to perform at the venue.
After the incident the sisters did two more songs before stopping to clean up.
But they say a guitar pedal had to be fixed and a limited edition electric guitar was damaged - costing them over £1,000 for them to carry on touring.
The pair, from Cape Town, have now sought legal action against venue landlord Paul Osmond after the incident, which happened on November 1 last year.
Mr Osmond, 45, from Hastings, said the fake blood was part of a ‘Halloween stunt’ and that he instructed two friends to throw blood, but not over the sisters.
He said the girls had been insulting to his sound manager before they performed.
Mr Osmond said: “I didn’t instruct them to throw it at them but it was a bit of fake blood and now they are absolutely rinsing it.
“For me those girls are the epitome of everything that is wrong with punk, they are absolutely awful.
“I am all for freedom of expression but I do not think what these girls are doing is that, they were pretty much naked when they played.
“If you want to get on stage and perform naked that is fine but there comes a point where that has a detrimental effect on the whole feminist movement.”
A Sussex Police spokesman confirmed the matter was being investigated.
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