Prominent Hamas official Mahmoud Zahar warned the West on Friday that assisting the "Zionist enemy" will result in confrontation, Israel Radio reported.

During a sermon at a Gaza mosque, Zahar called on the West to forbid Israel from using their land to enter Arab countries and kill Palestinians, as, he claimed, was the case with the assassination of Hamas man Mahmoud al-Mabhouh in Dubai last month.

"If the West will allow the Zionist enemy to turn its land into land where Muslim Palestinians are murdered, or leave from it in order to assassinate our men, we will confront it," Zahar said.

Earlier on Friday, Hamas security operative Nahro Massoud denied reports in the Israeli and British media claiming he was arrested in Damascus by Dubai authorities on suspicion that he was involved in assassinating al-Mabhouh.

Massoud told Hamas' Al-Aqsa TV that he was in Abu Dhabi ten days before the murder, and traveled from there to Damascus without being arrested. He went on to suggest that Fatah officials spread the rumor in an attempt to cover up the arrest of two Fatah men by Dubai authorities.

Hamas politburo chief Khaled Meshal has denied the allegation of Massoud's arrest, saying "It is not correct at all".

Hamas also said on Friday that the two Palestinians arrested in the killing were former members of the rival Fatah movement's security forces with links to senior Fatah's security official Mohammed Dahlan.

Dubai police have said they arrested two Palestinians among 18 suspects in last month's killing, which Hamas believes was carried out by Israel's Mossad. Dubai authorities have not identified the two Palestinians.

Hamas-affiliated Web site Palestine Information Center identified the two as Anwar Shheibar and Ahmad Hassanain.

It claimed Friday that both served in Fatah's security services and now work for a construction company owned by Dahlan. Fatah deny the charges.

On Thursday Haaretz learned that Shheibar and Hassanain were at one time members of the Palestinian Authority's security forces in Gaza, but after Hamas took over the Strip in June 2007, they fled to the West Bank and eventually moved to Dubai.

Hamas claimed that the senior Fatah official in question visited Dubai after the two were arrested and tried to persuade the authorities to release them, but without success.

London-based Arabic daily Al-Hayat quoted a senior Hamas official as saying that the two provided logistical aid to the alleged Mossad team by renting cars and hotel rooms for them, among other things.