Thousands of university students and other activists marched Saturday to protest President Bush's (searchvisit to this city already tense over security concerns.

Waving anti-U.S. placards and streamers saying "Ban Bush" and "Bush No. 1 terrorist," the protesters began their march at the sprawling University of the Philippines campus in suburban Quezon City (search). Authorities stopped them outside the House of Representatives building, where Bush addressed a joint session of Congress.

About 3,000 to 4,000 protesters gathered near the House, where they burned an effigy of Bush and five flags as the president's motorcade passed. In all, the protesters torched about 100 U.S. flags.

The crowd chanted: "Bush, Bush, go away, take with you GMA," a reference to Philippine President Gloria Macapagal Arroyo (search).

Rep. Liza Maza from the leftist political party Bayan-Muna donned a shawl showing a Filipino bird, a broken missile and "No to U.S. war." She distributed blue ribbons with "Legislators against war," which some of her colleagues wore on their shirts ahead of Bush's speech.

"I am opposed to the U.S. war on Iraq and elsewhere. It is unjustified," Maza said. "It is my responsibility to express my views on this issue."

Five legislators walked out of Bush's speech, but plan for a larger walkout fizzled.

Thousands of riot and traffic police were deployed on major thoroughfares to keep protesters away. Many downtown roads were blocked or traffic rerouted for Bush's motorcade, causing traffic jams.

At Ninoy Aquino International Airport, authorities halted or delayed some flights as part of stringent security measures.

Security was also tight at Manila train stations, where black-clad anti-terror police squads with bomb-sniffing dogs kept watch. In December 2000, 22 people were killed in a series of bomb attacks at one station and other places by suspected Muslim militants.

In Hong Kong, about 40 Filipinos marched to the U.S. consulate to protest against Bush's visit to the Philippines. They demanded that Bush stand trial for what they called "his crimes against humanity" during the U.S. invasions of Iraq and Afghanistan.