Thousands of farmers and students have clashed with police as they tried to reach the site of the World Trade Organisation conference in the Mexican resort of Cancun.
A South Korean man killed himself at the protest.
Lee Kyung-hae climbed onto a high security fence holding a banner that read 'WTO kills farmers'.
He then stabbed himself in the chest and died later in hospital.
About 5,000 activists joined the protest and about two dozen broke through eight foot high metal barriers to attack police on the edge of Cancun's upscale hotel zone.
Delegates at the WTO meeting are taking part in five days of discussions aimed at breaking a deadlock in the latest round of trade liberalisation negotiations.
The 146 member nations are seriously divided on a host of disputes, topped by agricultural subsidies in the United States and Europe.
