Large protests are taking place on the streets on the Philippine capital, Manila, where leaders are attending the Apec regional trade summit.
Hundreds of people from indigenous, student and labour groups clashed with police, who deployed water cannon.
The summit has been overshadowed by territorial disputes over China’s activities in the South China Sea.
Leaders have also called for greater global anti-terror co-operation following the Paris attacks.
A draft copy of a declaration due to be released later today says leaders at the Asia Pacific Economic Cooperation (Apec) summit “strongly condemn” all acts of terror and stress the “urgent need for increased international co-operation and solidarity in the fight against terrorism”.