Hamas's armed wing has said that the assassination of its political leader Ismail Haniyeh takes the war with Israel to "new levels," warning of repercussions for the entire region.

"The criminal assassination of leader Haniyeh in the heart of the Iranian capital is a watershed and dangerous event that takes the war to new levels and will have enormous consequences for the entire region," Qassam Brigades said in a statement.

The statement stressed that Israel had "miscalculated in expanding the circle of aggression and assassinating resistance leaders in various areas as well as violating the sovereignty of the region's countries."

Qassam Brigades noted that the continued Israeli crimes "must be an incentive for everyone to back and support the resistance in Palestine."

The Palestinian resistance group Hamas announced early on Wednesday that Haniyeh was killed in an Israeli air strike on his residence in the Iranian capital Tehran.

Israel has made no immediate announcement about the assassination.