Thai Police on Tuesday said they are hunting for a suspect, who they believe is connected to the bombing, which ripped through crowds gathered near the Erawan Shrine, in Bangkok.

On Monday evening, the explosion reportedly killed at least 22 people and injured about 120.

In a CCTV footage released by police, the man carried a dark-colored backpack near the shrine. In another, he no longer had the backpack. He was seen wearing a yellow T-shirt and dark-framed glasses.

Royal Thai Police Commissioner, Gen. Somyot Poompanmoung, said authorities don’t yet know the man’s identity or whether he is Thai or a foreigner.

Mr Poompanmoung said 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.

At a later news conference, police spokesman, Lt. Gen. Prawut Thavornsiri, said authorities were “very sure” the man in the yellow shirt was the bomber.

The Commissioner said the man sat down at 6:52 p.m on Monday and hid the backpack underneath a bench.

Investigators believe he left a pipe bomb.

The shrine, situated at a bustling intersection near a large shopping mall, is a big draw for tourists. At least seven people from other Asian countries were reported to be among the dead as well as one Briton.

The site is popular among Buddhists as well as Hindu and Sikh members of Thailand’s Indian community.

After being swarmed with police investigators on Tuesday, the shrine reopened to the public on Wednesday morning.

Prime Minister, Prayuth Chan-ocha, had described the incident as the worst-ever attack on Thailand.