ISIS has executed 25 people in Mosul, northern Iraq, by lowering them in a vat of nitric acid, according to several local news reports.

The men had been accused of spying on ISIS on behalf of Iraqi government security forces.

According to witnesses, the 25 alleged ‘spies’ had been tied together with a rope and lowered in a large basin containing nitric acid until their organs dissolved.

‘ISIS terrorist members executed 25 persons in Mosul on charges of spying and collaborating with Iraqi security forces,’ a source told Iraqi News in a statement.

‘ISIS members tied each person with a rope and lowered him in the tub, which contains nitric acid, till the victims organs dissolve.’