A UN investigator yesterday promised to be impartial in the probe into the Feb. 14 assassination of former Lebanese Prime Minister Rafik Hariri, a murder that has sparked anti-government demonstrations and international uproar. Peter Fitzgerald, the head of three-member UN team, started the investigation with meetings with Lebanese officials. The Lebanese government has insisted that it lead the inquiry but has expressed willingness to cooperate with foreign investigators. "I look forward to working closely with the Lebanese authorities, and to learning about their progress in investigating this terrible crime. We will also seek to speak to others who might assist us to fulfill our mandate," he told a news conference at a Beirut seafront hotel.Refusing to answer any questions from journalists, Fitzgerald, Ireland's deputy police commissioner, said in a prepared statement: "We fully understand the gravity of the task at hand, and can assure all concerned that we will work with absolute impartiality and professionalism." Fitzgerald said he would not be making any further public statements. The Irish investigator was expected to visit the seafront street where a powerful bomb hit Hariri's motorcade, killing 17 people and injuring more than 100. Justice Minister Adnan Addoum said the team would not be able to interrogate people but stressed that "whatever they want, any piece of information, laboratory test results, will be granted in cooperation with Lebanese authorities within the boundaries of Lebanese sovereignty." All efforts were being exerted to find the killers, Addoum said after the meeting. Interior Minister Suleiman Franjieh pledged after meeting with the team that "the state will provide them will all the information it has." The team was dispatched by UN Secretary-General Kofi Annan in response to a request from the Security Council that he urgently report on "the circumstances, causes and consequences" of Hariri's killing.