DUBAI: Dubai's police chief said he is almost certain Israeli agents were involved in killing a Hamas militant in the emirate, a newspaper said yesterday, raising the stakes in an escalating international row over the attack.

As Israel stuck to a policy of "ambiguity" on operations by its Mossad spy agency, London and Dublin summoned the Israeli ambassadors to explain why passport details of their citizens were used by the suspected hit squad.

Hamas sources also accused members of a rival Palestinian faction of helping Israel to kill Mahmoud al-Mabhouh, a top commander in the Palestinian Islamist group who was found dead in his luxury hotel room in January.