In Lebanon, the pro-Syrian government of Prime Minister Omar Karami resigned Monday following a massive demonstration in downtown Beirut by tens of thousands of anti-government protesters. Mr. Karami's resignation brought to a head a growing political crisis in Lebanon that was triggered two weeks ago by the assassination of former Prime Minister Rafik Hariri, one of the most powerful political figures in Lebanon.

In announcing the resignation of his government, Prime Minister Karami said he did not want to be an obstacle to the investigation of the killing of Rafiq Hariri.

Mr. Hariri, a five time prime minister and self-made billionaire, was killed February 14 in a bomb blast in Beirut. He had resigned as prime minister last October, following a dispute regarding Syrian influence in Lebanon. Many Lebanese opposition parties have blamed Syria for his assassination.

Since then, Lebanese citizens have staged massive protests demanding the government of Mr. Karami quit, and that Syria withdraw its 14,000 troops in Lebanon and end its political influence in the country.

On Monday, an estimated 60,000 Lebanese citizens defied a ban against demonstrations and staged a massive protest in downtown Beirut as the parliament met to debate a no confidence vote put forward by the opposition.

The Lebanese parliament is controlled by pro-Syrian legislators and would likely have been able to put aside the no-confidence vote, but Mr. Karami unexpectedly announced his resignation along with his administration.

As the news spread throughout the Lebanese capital, fireworks, cheers and car horns reverberated throughout the city. Tens of thousands of people waved red and white Lebanese flags. Many chanted for the resignation of Lebanon's pro-Syrian president, Emile Lahoud, as well as Syria's president, Bashar al-Assad.

Reacting to the resignation, opposition politician Walid Jumblatt said the people of Lebanon have been victorious. He called for the formation of an impartial government to oversee impartial elections, which would be held in May.

Following a meeting Monday with Lebanese Foreign Minister Mahmud Hammud, U.S. Middle East envoy David Satterfield again called on Syria to remove its troops before the election is held. He told reporters in Beirut that the elections must be fair and free.

Syria has been under increasing international pressure to pull its troops out of Lebanon and end its political dominance of its neighbor.