Thai police have released a sketch of the main suspect in the bomb attack that killed 20 people at Bangkok’s Erawan shrine on August 17.

According to Thailand’s chief of police, the attack was carried out by a “network”.

The man, dressed in a yellow T-shirt, was filmed by security cameras leaving a backpack at the shrine.

Erawan Hindu shrine, popular with tourists and Buddhists, reopened on August 19.

Thai police chief Somyot Poompanmoung told the Associated Press news agency on August 19 that the shrine attack was the work of more than one person.

“He didn’t do it alone for sure,” he said, referring to the main suspect.

“It’s a network,” he added, without giving further information.

Somyot Poompanmoung said he was certain that Thai citizens were involved in the bombing, but could not confirm if the bomber was a foreigner or a Thai citizen in disguise.

The prime minister has meanwhile urged the main suspect to surrender to the police because he might otherwise “get killed to stop him from talking”.

PM Prayuth Chan-ocha told reporters the man must have been hired to plant the bomb.

The shrine reopened at about 08:00 local time, with a handful of people arriving to place flowers or light incense in front of the slightly damaged statue of the Hindu god Brahma.

Most of the victims of Monday’s attack were Thai, but nationals from China, Hong Kong, the UK, Indonesia, Malaysia and Singapore were among the foreigners killed.

No-one has yet said they carried out the attack.

In a separate attack on August 18, an explosive device was thrown at a pier in Bangkok. No-one was hurt, but the authorities have not ruled out a link between the incidents.