Karami said only that he was concerned that some might see his government as an obstacle to progress before announcing to a shocked chamber that he was leaving office.
"I thank the deputies who assured me their vote of confidence for the government," Karami said. "Because of my concern that the government may become seen by some as an obstacle to the good of the country, I announce the resignation of the government I had the honor to lead."
Politicians and analysts in Beirut say Karami apparently took criticism aimed at his government personally and, in the words of one politician, "felt injured." They say they do not believe Syria forced him to go.
Widespread reports on 1 March say President Emil Lahoud had asked Karami to delay his resignation by a day or two so that the presidency could deal with its aftershocks. Karami apparently refused.
Former Prime Minister Selim Hoss told RFE/RL that Karami's resignation creates a political vacuum that could prove dangerous. "Yes, it is dangerous," Hoss said. "This void can be filled only if the opposition is ready to engage in a process of consultations that is [in accord with] our constitution. I am one of the ones who is fearful now, today, that this might not come about soon enough. The opposition is still reluctant to open up to the president."
That opposition, led by maverick Walid Jumblatt, said it will meet on 2 March to decide what steps to take. There has been bad blood between the opposition and the president who, like Karami, is perceived as a Syrian ally.
Presidential spokesman Rafik Shalala says the president will start consultations with parliament Speaker Nabih Berri on 2 March on choosing a caretaker prime minister until elections can be held in April. Shalala did not say whether the president is willing to deal directly with Jumblatt, although indirect talks are believed to have started.
Among the names mentioned as possible opposition nominees for the caretaker position are Hariri's sister, a former minister of justice and the current finance minister. Both ministers are former allies of Hariri.
The speech by Hariri's sister, Bohiye, during a parliament session on 28 February, is said to have been the one that upset Karami most and caused him to resign. In her speech, Hariri called for the cabinet's resignation and a full investigation into the killing of the former prime minister.
Although Karami will stay in office until the parliament has approved the president's new nominee for the post, Hoss said it is unlikely the current government will continue to perform its duties. That, he said, is a cause for concern because anything, even violence, can take place.
"In practice, under the circumstances, I cannot imagine any of the ministers going to [the] office to conduct the daily affairs of his portfolio," Hoss said. "I cannot imagine. So I am afraid, very much afraid, that there would not be a minimum of the government in the country and this would open up the situation to any possibility."
Following Karami's resignation, the office of a pro-Karami deputy was ransacked, and there were reports that antigovernment elements attacked a Karami statue in Tripoli, the prime minister's hometown.
Meanwhile, Hoss on 28 February announced he is forming a "third front" of intellectuals, technocrats, and a few politicians. He said he hopes the new movement can act as buffer between supporters of Karami and Lahoud, on one hand, and Jumblatt and the opposition, on the other.