An underground pro-Iranian group that holds a Belgian doctor hostage in Lebanon claimed responsibility Friday for the slaying this week of two Moslem clerics in Brussels, accusing them of spying for Israel.

"On the basis of our conviction to fight the enemies of God and Islam, our group announces that it has executed God's sentence against the traitors Abdullah Ahdel and Salem El Behir in Brussels on March 29, 1989," The Soldiers of Truth Organization said in a statement.It was the first claim of responsibility for the double murder of Ahdel, 35, the Saudi Arabian director of the Islamic Cultural Center in Brussels, and El Behir, 48, a Tunisian librarian at the center, who were found shot to death Wednesday at Brussels' main mosque.