CAIRO, Egypt  —  An Egyptian opposition leader and presidential hopeful whose imprisonment angered Washington and called into question Egypt's (search) pledges of democratic reform was released Saturday on bail.

Ayman Nour (search), frail and still wearing his prison jump suit, stepped out of Cairo's (search) police headquarters and flashed a V-for-victory sign to a waiting crowd of supporters.

Word spread fast of the 40-year-old lawmaker's release, and within 15 minutes, a crowd of 400 supporters swelled to a few thousand. Firecrackers popped on the streets and members of the crowd threw candy in the air and trilled with joy.

"We are paying the price of our search for freedom," Nour said. "They tried for days to destroy a national project, the Tomorrow Party. But they failed."

As the crowd cheered, Nour repeated last week's jailhouse announcement that he would run for president this year against 24-year incumbent Hosni Mubarak.

"I announce that I will run in the presidential elections for you," Nour said.

Nour promised to run for office shortly after Mubarak gave the surprise order that the constitution be amended to permit multi-candidate elections later this year.

Mubarak, as the sole candidate, has won every presidential referendum since 1981.

Nour and his political party have maintained that the accusations against him were an effort from the ruling party to eliminate him as a political rival. Nour has not been charged with any crime, but he was accused of presenting fraudulent signatures to a government committee to get a license for his party. He has denied the accusations.

Washington called Nour's release a positive development.

"We welcome the release today of Ayman Nour," said Lou Fintor, a State Department spokesman. "We look forward to steps Egypt will be taking over the coming months to expand political participation."

Nour's Tomorrow Party was not approved until late last year, and was only the third to be legalized in the past 25 years. It has only seven legislators in Egypt's 454-seat parliament. Nour's detention since January drew wide attention, partly because he had championed the call for multi-candidate presidential elections.

Secretary of State Condoleezza Rice said she raised "very strong concerns" about Nour when she met Egyptian Foreign Minister Ahmed Aboul Gheit in Washington last month.

International human rights groups had also had called on Egypt to release Nour, saying his detention was politically motivated.

When Nour was released, his wife, Gamila Ismail, quickly hugged him.

"I am so happy. Ayman is of the people, for the people. He was never a stooge of the authorities," she said, watching her husband being carried on the shoulders of his supporters.

Prosecutor-general Maher Abdel Wahed ordered Nour's release on $1,725 bail, saying the reasons for his provisional detention had ended. He said how to handle the case would be determined soon, insisting it was a "criminal" not a "political" case.

"Now, we hope that Ayman will be referred to a fair and quick trial," Hmeida said.

Egyptian security kept a low profile during Nour's release, with only two armored cars parked nearby as supporters chanted.

The show of support was quickly translated into election campaigning. His party's deputy secretary general, Ragab Heilal Hmeida, called the welcome a "renewal of his popularity."

"He has great weight, not only in the area, but in the whole of Egypt," Hmeida said.