A Palestinian NGO has condemned the terrorist group Hamas, which rules the Gaza Strip, for issuing death sentences to three alleged Israeli spies.

A 57-year-old man from Gaza City was convicted on Tuesday of sharing intelligence with Israel for over 20 years, allegedly providing information about Hamas’ tunnels, rockets, and safe houses, Palestinian media reported. He was sentenced to death by firing squad; two other men were convicted and condemned to die by hanging. In response, the Gaza City-based Palestinian Center for Human Rights called the punishment “excessive,” stating that “civilians should not appear before military courts.”

According to Palestinian law, “collaboration” with a foreign state “is punished with life imprisonment with hard labor. The act is punishable by execution if it had repercussions.” Executions must also be approved by the president of the Palestinian Authority, but PA President Mahmoud Abbas, who placed a moratorium on death sentences in 2005, has no de facto authority in Hamas-run Gaza. The United Nations condemned Hamas in May after it announced its plans to carry out 13 public executions, saying that it had “serious doubts” that its trials had the necessary international legal standards of fairness to impose the death penalty in the first place, and noted that the executions are likely extrajudicial because Abbas did not approve them. The executions were later carried out.

Hamas also executed one of its own commanders in March on charges of “moral turpitude”—commonly understood to be a code for homosexuality, The New York Times reported. Amnesty International condemned Hamas in 2014 for carrying out 23 executions during its war against Israel, including six public killings.