Lebanese opposition supporters have held a rally in Beirut demanding the resignation of the government, in defiance of a ban on demonstrations.
The Beirut rally saw only minor scuffles with police
About 10,000 protesters - many of whom waved Lebanese flags - also called on Syria to withdraw from Lebanon.
Many demonstrators blame Syria for the recent killing of former Lebanese Prime Minister Rafik Hariri.
The rally comes as parliament meets to discuss an opposition-sponsored motion of no-confidence in the cabinet.
MPs observed a minute's silence in memory of Hariri as the debate began on Monday.
Prime Minister Omar Karami - who took office after Hariri resigned in last year - said those who accused his government of responsibility in the killing committed a "grave injustice".
Outside parliament opposition supporters called on the cabinet to stand down and chanted: "We want no other army in Lebanon except the Lebanese army!"
Opposition leader Akram Shehayeb urged soldiers nearby to join the rally.
Beating the ban
The protestors had spent the night on Martyrs Square wrapped in blankets or under tents, before the ban on demonstration came into force at 0500 (0300 GMT).
Army checkpoints on roads into Beirut turned away cars and buses carrying people into the city.
Government supporters have also been mobilising
But there have been no reports of soldiers taking any action against the protestors who were already in the city centre.
As the protest began US Deputy Assistant Secretary of State David Satterfield met Lebanese Foreign Minister Mahmoud Hammoud.
Mr Satterfield on Sunday called for a "credible investigation" into Mr Hariri's killing, and reiterated Washington's demand that Syria withdraw its troops from Lebanon "as soon as possible".
Lebanon has said it will allow external experts to aid the inquiry into the assassination, but has dismissed US and French demands for a full international investigation.
Opposition leader Walid Jumblatt on Monday urged MPs to vote against the government.
"We don't want Lebanese and Syrian intelligence controlling Lebanon," he added.
Syria denies being responsible for the massive car bombing that killed Mr Hariri two weeks ago.
Following the assassination, Damascus has come under fresh pressure from the international community to withdraw from Lebanon.
Many schools and businesses remained shut across Lebanon on Monday, following a call by the opposition for a general strike.
Syrian Foreign Minister Farouk al-Sharaa has rejected calls for a full withdrawal from Lebanon, saying this is something not even the Lebanese want.
Damascus said last week that it would draw it troops back from western Lebanon to areas nearer the Syrian border, though it did not specify when.
The Syrian presence is expected to be a key issue in elections due to be held in Lebanon this summer.