Osama Hamdan, the militant group's representative in Lebanon, said in an interview with Beirut's daily al-Mustaqbal, the cooperation between Israel's intelligence agency, Mossad, and the intelligence service of an Arab country helped Israel assassinate a Hamas activist in Damascus last week.
"We had taken extra security precautions before we were tipped about that cooperation ... We later found out that the security services of an Arab country that is a neighbor of Palestine provided Israel with all the information about Hamas," Hamdan said.
Israel had threatened to hit Hamas leaders outside the Palestinian territories.
Hamdan said Hamas is currently considering the possibility of hitting at Israelis outside the Jewish state in response to Israel's operations against the group's exiled cadres.
"The issue is under scrutiny and we hope the enemy will not repeat such assassinations, because if that happened it will affect our decision to respond similarly," he added.