A report by Amnesty International has accused the Hamas of carrying out abductions, torture and killings of at least 23 Palestinians in 2014.
An ABC News report has suggested that the Hamas used last year's war with Israel along the Gaza Strip to carry out revenge attacks against their opponents.
The victims were accused of collaborating with Israel. Many of them were already in prison over charges of acting for the enemy.
According to Amnesty International, there is evidence of at least 23 ex-judicial killings.
Amnesty International researcher Saleh Hijazi said these people have been accused by Hamas of assisting Israel in military operations.
