An international human rights group says spyware developed by an Israeli cyber-surveillance firm was used to hack mobile phones belonging to Palestinian activists.
Amnesty International announced on Monday that analysis indicates six devices were hacked, which belonged to six Palestinian human rights defenders.
It said NSO Group's Pegasus spyware was used.
Palestinian human rights groups strongly condemned the alleged hacking and indicated they would seek an investigation by the United Nations or other organizations.
Noting that NSO Group's headquarters is in Israel, one official said, "Therefore, the occupying country is responsible and such software should never be used to violate human rights."
NSO Group has denied any involvement. Pegasus spyware gives users access to data on a target's phone and is said to have been used to monitor people such as politicians and journalists around the world.
The US Commerce Department announced last week it was virtually banning NSO Group from trade with the US, citing that its spyware goes against national interests.