Syrian President Bashar Assad made surprise trips to Saudi Arabia and Egypt on Sunday, apparently seeking support from Arab leaders as he faces a U.N. probe into alleged Syrian involvement in the assassination of a former Lebanese leader. Arab diplomats said the trips were aimed at finding a face-saving way for Assad to handle U.N. requests to interview him about the Feb. 14 killing of former Lebanese Prime Minister Rafik Hariri in a Beirut bombing. The trips come despite warning that if he leaves Syria his opponents may use the opportunity to seize power in the country, Israel Radio reported. The Arab daily Al Quds al-Aribye reported that the intelligence services of a neighboring country, as well as Russia, sent the warning to Syria. Assad ignored the warnings and left Syria for Jiddah, Saudi Arabia, to meet the Saudi King Abdullah, and Sharm el-Sheikh in Egypt to meet President Hosni Mubarak. Assad implied in a newspaper interview published Saturday that he has rejected U.N. investigators' second request to interview him on the grounds that he has international immunity. The diplomats, who spoke on condition of anonymity because of the sensitivity of the talks, said one proposal put to Assad called for him to send an envoy to take investigators' questions. Assad would then respond in writing. The diplomats also said Assad is seeking stronger Arab support for Syria - including convening an Arab summit to discuss Syria's strained relations with the West. Syria's former vice president Abdul-Halim Khaddam, who defected to France, said in a series of recent interviews that Assad had threatened Hariri during their last meeting. Assad has denied the charge. Assad flew to the Saudi port city of Jiddah, where he met with King Abdullah. Hariri was closely aligned with Saudi Arabia. A joint Saudi-Syrian statement issued afterward said the two discussed regional issues, including Iraq and the Palestinian territories. Abdullah stressed the kingdom's desire to "improve relations between Syria and Lebanon and strengthen them in a way that safeguards the interests of both countries and the security of the region," according to a statement carried by Syria's official news agency, SANA. Assad later traveled to Sharm el-Sheik, Egypt, for a meeting with President Hosni Mubarak, SANA said. The United Nations inquiry into Hariri's killing has implicated the Syrian government and accused it of failing to cooperate fully with the probe. That prompted the Security Council to warn Syria that it faced "further isolation" by the international community. The accusations against Syria and the hasty withdrawal of Syrian forces from Lebanon in April brought relations between the neighbors to their lowest point since they gained independence from France in 1943. Beirut's staunchly anti-Syrian An-Nahar newspaper quoted Khaddam as having told French RTL radio that he had met with Detlev Mehlis, the outgoing head of the Hariri investigation team, in Paris and gave him "specific facts" about Hariri's assassination. "Naturally, the investigations team's work is secret and I have no right to reveal them," Khaddam was quoted as saying. The Syrian parliament last week accused Khaddam, who has been living with his family in Paris for the past few months while writing a book, of high treason. The government has seized his assets.