Reports indicate Hamas killed 18 suspected Israeli informants following the Israeli airstrike that left three Hamas commanders dead.
Thursday an Israeli strike killed three top military officials in a home near Rafah, and it appears Hamas suspected Israel learned of their location from informants.
In a statement Hamas said Israel "will pay a heavy price" for killing the commanders.
Witnesses say Hamas killed the suspects at an abandoned police station and outside a mosque. They also say the group dropped off some of the bodies at a hospital.
The Palestinian Center for Human Rights says two of those killed in the massacre were women.
The group posted this press release asking the Palestinian National Authority and resistance groups to stop executions without trial.
But it appears Hamas has no plans to halt the executions, as Fox News reports Hamas media is portraying the killings "as the beginning of a new crackdown" against any enemy collaborators.
This is the third time Hamas has announced killing suspected collaborators since the outbreak of fighting six weeks ago.
