According to the London-based Saudi daily Al-Sharq al-Awsat, Serge Brammertz, the United Nations investigator looking into the assassination of the late Lebanese prime minister Rafiq Hariri, is now almost certain there was an underground blast in the operation. Brammertz apparently increasingly believes that there were, in fact, two blasts, one above ground and one below, a theory initially raised privately by members of the Hariri family. This is not the first time that the hypothesis has resurfaced, but this time there is much more to suggest that Brammertz is indeed thinking along these lines. I've heard from a very reliable UN source that investigators have found new information from the blast site, and in his first report, dated March 14, Brammertz noted that his team had "also further examined the possibility of an aboveground, underground or combination impact."
An underground explosion would virtually seal the murder as a Syrian-led operation, since only the Syrians would have had the bureaucratic means, and influence, to organize the road works needed to plant a device of that magnitude. I've also heard that one of the more important of the four Lebanese generals arrested on suspicion of participating in the crime has started to spill the beans, has given several names of other participants, and is requesting witness protection. According to the source, President Emile Lahoud's recent request for the generals to be released was at least partly designed to prevent this from happening, given the central role allegedly played by the general in the plot.
A third thing I have heard, this from several sources, is that the Syrian witness Houssam Houssam, who alleged that the Hariri family had tried to compel him to present false testimony to UN investigators, and who appeared in Damascus last year to blacken the investigation, was driven to the Syrian border and, therefore, removed from Lebanese custody, by Hezbollah. This information, like that of the general who has started to talk, must of course be confirmed, but is what is circulating in political circles in Beirut.
For an English-language summary of the Al-Sharq al-Awsat piece, go here.