JEFFREY BROWN: A short time ago, I spoke with Abigail Fielding-Smith of The Financial Times from Beirut.
Tell us a bit more about the presumed target here, a top intelligence official. How has he stirred up enemies?
ABIGAIL FIELDING-SMITH, The Financial Times: Well, he was one of the most senior intelligence officials in Lebanon.
And he was associated with a couple of particular things which really targeted Syria and Syria allies in Lebanon. One was the investigation into the murder of former Prime Minister Rafik Hariri in 2005.
And most recently he was seen as being involved in the arrest of Michel Samaha, who was one of the Syrian President Bashar al-Assad's top allies in Lebanon, which was seen as a very bold move for the intelligence services in Lebanon.
JEFFREY BROWN: No one has taken responsibility for the bombing yet, I gather. So, what is the thinking there? What is being talked about? Who is being looked at?
ABIGAIL FIELDING-SMITH: Well, politicians in Lebanon who are associated with the sort of anti-Assad movement have been very quick to blame Assad.
And for many Lebanese, the bomb today -- it was a huge blast -- was reminiscent of a string of attacks which took place against anti-Syrian politicians in the years 2005 to 2008.
So there's a lot of people targeting the Syrians for this, although Syria has condemned the attack and described it as an act of terrorism.
But there are protests in areas of Lebanon sort of associated with opposition to the Syrian regime today. So the mood on the street at least in those areas is very angry.
JEFFREY BROWN: Well, you know, as you say, there is a lot of history there between Syria and Lebanon, but how is this -- what is going on in Syria now, how is it spilling over, how is it playing out in Lebanon? What force has that unleashed there?
ABIGAIL FIELDING-SMITH: Well, I think there's been two types of things.
First of all, there is the sort of literal spillover. There's been a lot of clashes on the Syrian-Lebanese border where a lot of Syrian rebels are believed to be sort of seeking refuge.
And, also, there's been a lot of refugees pouring into Lebanon, which is quite a small country. They have had about 70,000 refugees. So that's also increased tensions.
Another way in which it has increased the sort of political temperature here is that it is made the sort of predominantly Sunni opposition of Lebanon who are close to the opposition in Syria more empowered and more angry with Syria's allies in Lebanon.
So in many ways, these tensions preexisted the Syrian crisis. But the Syrian crisis has inflamed them. And, you know, particularly when you have things like Lebanese citizens getting kidnapped in Syria, as happened during the summer, it really sort of inflames things and makes the situation in Lebanon very unstable.
JEFFREY BROWN: And what about the role of Hezbollah? The U.S. recently said it's become part of the Syrian government's killing machine, was the way they put it, I believe. How much is known about Hezbollah's role in what is going on both in Lebanon and vis-a-vis Syria?
ABIGAIL FIELDING-SMITH: Well, you know, Hezbollah themselves deny sending fighters to Syria.
But there have been these reports of funerals of Hezbollah members who are widely reported to have died in Syria. Not very much is actually sort of known about it in terms of facts.
What we do know is that Hezbollah is closely allied with the Syrian regime. They see sort of an alliance of interests together. And that has actually cost Hezbollah politically in Lebanon, being so publicly associated with the Syrian regime.
JEFFREY BROWN: Well, let me just ask you finally, Abigail, personally there, what's the tension level at this point? How close does it feel to a return to the kind of sectarian violence of the past?
ABIGAIL FIELDING-SMITH: Well, I mean, I don't know about sectarian violence, but certainly the people I saw today sort of around the site of this massive bomb blast looked, you know, extremely disappointed that their country had gone back to a pattern of behavior that everybody hoped that it left behind.
Beirut itself, the central Beirut, the streets that I have just driven in to get to the studio are quiet, much quieter than usual. But I haven't seen any actual sort of burning tires or anything on the streets.
I think the coming days will show whether the political leadership on both sides in Lebanon is really able to kind of contain the tensions provoked by events like this.
JEFFREY BROWN: Abigail Fielding-Smith of The Financial Times in Beirut, thanks so much.
ABIGAIL FIELDING-SMITH: Thanks.
JEFFREY BROWN: Immediate reports of the explosion were captured on Twitter today. On our website, you will find a timeline of these tweets from journalists who were at the scene.