Thousands of demonstrators have gathered in downtown Santiago to protest the start of the Asia Pacific Economic Cooperation summit.
Officials said Friday up to 10,000 people are participating in a peaceful, government authorized demonstration. Earlier, police used water cannon and teargas to break up a group of rock throwing protesters opposed to the war in Iraq and the pending arrival of President Bush in the Chilean capital.
Heads of state from 21 Pacific rim countries are scheduled to attend the two-day weekend conference, which will focus on terrorism, nuclear proliferation and global trade.
In preparation for the summit, foreign and trade ministers agreed Thursday on a broad anti-terrorism resolution, including implementing additional maritime and aviation security measures in the next two years.