Updated on August 20 at 12:21 p.m.
“Security agencies have collaborated with intelligence agencies from allied countries and have come to the same preliminary conclusion that the incident is unlikely to be linked to international terrorism,” military spokesman Col. Winthai Suvaree said in a televised statement.
But he later told The Associated Press it was too soon to draw any conclusions.
“We still have to investigate in more detail,” he said.
Officials released security footage this week that showed a man in a yellow T-shirt and shorts walking near Bangkok’s Erawan shrine carrying a backpack. He is then seen sitting on a bench, removing his backpack and walking off. The explosion occurred about 15 minutes later, killing 20 people and injuring more than 100.
On Wednesday, police issued an arrest warrant for the man, whom they described as tall and “foreign." They said he had a prominent nose, thick lips, and a fair complexion.
A $28,000 reward for information leading to his arrest was increased Thursday to $56,000.