CAIRO, Nov 26 (Aswat Masriya) - An Islamist coalition has called for mass protests on Friday, which marks a 100-day anniversary of the Abu Zaabal Prison incident where at least 37 people died from suffocation.

The National Alliance for Supporting Legitimacy, founded in support of ousted President Mohamed Mursi, described the incident as a "holocaust".

The prisoners suffocated from teargas while being deported following clashes between them and the security forces after a failed escape attempt, according to the interior ministry's statement.

"Demonstrating on Friday will be to remind the coup organisers of their crimes and renew our oath to bring a just and speedy retribution to all martyrs," said a statement released by the coalition on Tuesday.

The prosecutor-general has referred four police officers to trial on charges of negligence and attempted murder of the prisoners.

Investigations had revealed that the ventilation system in the deportation car did not work and that there were 45 prisoners inside the car, which is more than its capacity.

The Islamist alliance has called for week-long protests to mark 100 days since the security crackdown on two pro-Mursi protest camps that were held in Cairo where around a thousand people died.

Mursi was ousted by the military following mass protests against his rule on June 30.