Original:  However, Time magazine cited a "western intelligence source" as saying that Mossad was behind the blast, and other reports, which were attributed to western intelligence services , also mentioned the involvement of Israel's intelligence services.
Revised:  However, Time magazine reported claims from a "western intelligence source" as saying that Mossad was behind the blast, and other reports, which were attributed to western intelligence services , also mentioned the involvement of Israel's intelligence services.
Edit intent: clarity