Thousands of Hezbollah supporters are camped out in Beirut for a second day, demanding Lebanon's U.S.-backed government to resign.

Protesters broke the early morning silence Saturday with anti-government chants and nationalist songs. The mainly peaceful opposition demonstration continued into the day.

On Friday, hundreds of thousands of people rallied in the capital. Many protesters then pitched tents on streets leading to the heavily barricaded offices of Prime Minister Fuad Siniora, who has been holed up inside.

The demonstrators say they will not move until Mr. Siniora resigns.

Hezbollah, a Shi'ite militant group, is demanding a new national unity government.

Prime Minister Siniora has vowed to resist efforts to oust him. He says there is no way to remove a government except through parliament.

In Washington, a State Department spokesman, Tom Casey, said the United States is very concerned that Hezbollah and its allies, with the support of Iran and Syria, are trying to destabilize Lebanon. The spokesman said the U.S. is committed to supporting Lebanon's democratic government.

Tensions have been high in Beirut since the November 21 assassination of anti-Syrian Christian politician Pierre Gemayel.

Some information for this report was provided by AP, AFP and Reuters.