A man wearing a yellow T-shirt and carrying a backpack is seen walking near the Erawan shrine, where a bomb blast killed 22 people on Monday, in Bangkok, Thailand in this handout still image taken from closed-circuit television (CCTV) footage, released by the Thai Police on August 18, 2015.

Thai police on Wednesday offered a reward of 1 million baht (28,100 U.S. dollars) for any information leading to the capture of a suspect of Monday explosion in Bangkok.

Thai authorities say the explosion killed no fewer than 20 people and wounded more than 100 others.

The police released a sketch of the suspected perpetrator who was seen on a surveillance camera at the scene.

Camera footage showed that the suspect is a foreign-looking, young man, who was wearing a yellow T-shirt and glasses.

He had left a backpack purportedly with some dynamite inside at Erawan Shrine, a popular tourist destination in downtown Bangkok, shortly before the explosion.

The shrine reopened Wednesday morning amid heightened security, but far fewer tourists visited it than before.

Thai Prime Minister, Prayut Chan-o-Cha, urged the `amateur’ culprit to surrender himself to the police, warning he could otherwise be killed.

“The bombing suspect could probably be killed if he did not surrender for his own safety.

“His life is being fatally jeopardised by those who had hired him and might be looking to silence him,” Prayut said.

Meanwhile, police chief, Somyot Poompanmoung, believed that the bombing was carried out by `a network.’

Chinese Embassy in Bangkok said on Wednesday that six Chinese nationals, including four from the mainland and two from the Hong Kong Special Administrative Region, have killed in the blast.

(Xinhua/NAN)