April 12 (Bloomberg) -- Thailand declared a state of emergency in Bangkok as violence broke out across the capital after police arrested the leader of an anti-government protest group that stormed a regional leaders’ summit yesterday, forcing its cancellation.

“We announce the state of emergency and related announcements to give legal power to the government to restore order and bring back normalcy as soon as possible,” Prime Minister Abhisit Vejjajiva said on state-run television. “The government will try to prevent any losses. We hope to get support from the public to bring peace to the nation.”

Thailand canceled a regional leaders’ summit yesterday in the resort town of Pattaya after anti-government protesters disrupted meetings, deepening a crisis that adds pressure on Abhisit, 44, to resign or call an early election. He said today he may consider his political future after “normalcy” returns.

Leaders from the 10-member Association of Southeast Asian Nations were scheduled to meet with counterparts from China, Japan, South Korea, India, Australia and New Zealand this weekend in the resort town of Pattaya. All returned home after the summit was canceled yesterday afternoon.