Two people charged in the 2012 Baldia Town factory fire that killed more than 250 people were sentenced to death by the Pakistani anti-terrorism court Tuesday.

The convicted belong to the Muttahida Qaumi Movement, a secular political party in Pakistan. Prosecutors alleged that the factory was torched in retaliation for the owners refusing to pay an extortion demand.

Four others, also members of MQM, were released for lack of evidence. Three security guards at the plant were previously convicted, also receiving life sentences.

Prosecutors rested their case on September 2 after presenting forensic, ballistic and chemical analysis and testimony from 400 witnesses.

“Ali Enterprises,” located in Baldia Town area of the nation’s capital, Karachi, exported garment to the United States and Europe. On September 11, 2012, a fire believed to have been arson destroyed the privately owned factory, leaving a tremendous death toll.

The initial investigation following the fire led to charges of negligence against the factory owners. Exit doors were locked and windows covered with iron bars, making escape difficult.

However, a subsequent government report in 2015 brought forth the first allegations of extortion regarding the fire.