An Iraqi court on Wednesday sentenced 24 alleged Islamic State group militants to death for their role in the massacre of hundreds of soldiers in the city of Tikrit. Four others were acquitted for lack of evidence.

ISIS militants captured the soldiers after the militant group seized the city of Tikrit last year as they were fleeing from the former U.S. military base Camp Speicher.

Video footage that surfaced online a year ago showed hundreds of soldiers being forced to lie facedown in shallow ditches and executed. Nonprofit organization Human Rights Watch has called it the "largest reported incident" of armed violent abuse in Iraq where "ISIS captured more than a thousand soldiers fleeing Camp Speicher, near Tikrit, then summarily executed at least 800 of them."

The men were sentenced within hours of the trial's start due to strong evidence against them "including the confessions of the defendants in the investigation phase, which matched the facts and the records of forensic evidence," court spokesman Abdul Sattar Bayrakdar said, according to CNN. He added that all of those sentenced were Iraqi nationals and another 604 suspects were still wanted.

All of the defendants pleaded not guilty, claiming that they never took part in the massacre, and that their confessions were extracted under torture by Iraqi authorities.

Iraqi criminal lawyer Tariq Harib said that the sentences would be sent to a higher court for approval within a month, Reuters reported.

The ruling comes after Iraqi security forces arrested dozens of people allegedly linked to the massacre, largely from Salaheddin province, north of capital Baghdad.

Tikrit was reclaimed by Iraqi army troops and Shia militia forces in March, and mass graves of some of the soldiers thought to have been killed by ISIS fighters have been exhumed by Iraqi forensic teams. Video footage posted online reportedly showed bodies being dumped into the nearby Tigris River, making it difficult to estimate the massacre's final death toll.