An official from the Syria-based leadership of the Islamic Jihad militant group claimed responsibility Saturday for the suicide bombing that killed four Israelis in Tel Aviv. The official, reached by telephone in Lebanon, contradicted a denial issued by the militant group in the Palestinian territories shortly after the suicide attack on the Tel Aviv beachfront just before midnight Friday. The two other main militant groups — Hamas and the Al Aqsa Martyrs' Brigades — also denied involvement, as has the Iranian-backed, Lebanese-based Hezbollah.Palestinian security officials had pointed to Hezbollah, which has been trying to disrupt an informal Mideast truce agreed to Feb. 8. Palestinian police arrested two suspected militants in connection with the nightclub bombing, and local security officials in the northern West Bank town of Tulkarem said the suspects had ties to Islamic Jihad.