A sketch of the main suspect in the deadly bombing of a Bangkok shrine and tourist spot was released Wednesday as Thailand's prime minister urged him to surrender to authorities.
The drawing shows a young man with glasses and is apparently based on the person seen in surveillance video leaving a backpack near the scene on Monday.
Police are offering a 1 million baht ($28,080) reward for information leading to his arrest.
Officials said they were keeping watch for the suspect at the country's borders, but police chief Somyot Pumpanmuang told a news conference that it was not clear how many people were involved in the attack or if they were still in the country.
"I don't suspect one person, I suspect many people," he said. "I am confident that there are Thais involved but I am not saying it is just Thais or that there are foreigners."
Prime Minister Prayuth Chan-ocha appealed to the man in the video to come forward, warning that the suspect "might get killed to stop him from talking."
Police said the sketch was also partly based on a description provided by a motorcycle taxi driver believed to have given the suspect a ride on the night of the blast.
The open-air Erawan Shrine reopened to the public Wednesday, two days after the explosion tore through the area killing at least 20 people — including foreigners — and wounding more than 120 injured.
No group has claimed responsibility.
Prayuth told reporters: "If the person wants to be safe, he should turn himself in. Officials will find a legal way to provide him with safety. It's better than living in hiding. It would make his life miserable."
He added: "I want to tell those close to the suspect to tell him to come to police, whether you are in the same network or not, because he might be in danger."