LONDON - Human rights violations in both the Gaza Strip and the West Bank have become widespread since fighting in June between the Palestinian factions saw Hamas seize control of Gaza, Amnesty International said on Wednesday.

"Arbitrary detentions and torture or other ill treatment of detainees by Hamas forces are now widespread and the initial improvements in the security situation which followed Hamas' takeover are fast being eroded," the group said in a report.

The rights watchdog also accused Palestinian President Mahmoud Abbas's Fatah-dominated forces of abuses in the larger West Bank, where Fatah retained control after its rout in Gaza.

"Arbitrary detention of suspected Hamas supporters by Palestinian Authority security forces has become routine," it said.