DUBAI (AFP) - Pressure mounted on Israel on Thursday as Australia joined a growing list of countries angered by the use of their passports in the Dubai killing by suspected Mossad agents of a top Hamas leader. Irish Foreign Minister Micheal Martin said his government was very angry over the suspected use of forged Irish passports by the assassins. France said the killers had used three forged French passports to travel to Dubai. We are very angry at the fraudulent use of information that was stolen from valid Irish passports to make forged passports, Martin said during a visit to the Gaza Strip, which has been controlled by the Hamas movement since June 2007. These people were not Irish citizens. Whoever did this forged the passports. Were angry about that because it violates the integrity of our passport system and also places at risk the security of our citizens. Australia summoned the Israeli ambassador to discuss the latest development in the investigation into the killing, which Dubais police chief has said was almost certainly carried out by agents of the Israeli intelligence service. Australia will not be silent on the matter, said Prime Minister Kevin Rudd after three Australian passport-holders were named among 15 new suspects linked to last months killing of Mahmud al-Mabhuh. If Australian passports are being used or forged by any state, let alone for the purpose of assassination, this is of the deepest concern and we are getting to the bottom of this now, Rudd told public broadcaster ABC. We will not leave a single stone unturned. Australian Foreign Minister Stephen Smith, who summoned Israeli ambassador Yuval Rotem for an explanation Thursday, said initial investigations showed the Australian passports were probably duplicated or altered. I made it crystal clear to the ambassador that if the results of that investigation cause us to come to the conclusion that the abuse of Australian passports was in any way sponsored or condoned by Israeli officials, then Australia would not regard that as the act of a friend. In addition, three Palestinians are being questioned over the killing, the paper said. Dubai police have previously announced that they have in custody two Palestinians, both residents of the emirate who had fled but were extradited back from Jordan. Palestinian foreign minister Riyad al-Maliki described the investigation as very professional, adding that Palestinian officials were in constant contact with Dubai investigators. The international police agency Interpol last week relayed arrest warrants, or so-called Red Notices, for the initial 11 suspects wanted by Dubai, but it declined to give further information on Thursday.