Update as of 1:20 a.m. EDT: Relatives have claimed the bodies of the victims of Bangkok’s Erawan Shrine blast at a forensic institute Thursday, the Associated Press (AP) reported. The bombing at the Hindu shrine Monday killed at least 21 people and wounded 123 others.

Gao Yu Zhu, a 50-year-old Chinese national, was reportedly overwhelmed by grief while he waited to retrieve the bodies of his daughter Gao Yu Zhu and his wife Huang Lu Yan.

No one has claimed responsibility for the blast.

Original story:

Thailand is seeking help from Interpol to track down a suspect believed to have detonated an explosive at Bangkok's Erawan Shrine Monday that killed at least 21 people Monday, according to reports Thursday. The bombing involved at least 10 people and was planned a month in advance, Reuters reported, citing Thai police chief Somyot Poompanmoung.

"We sent a request for assistance," Kissana Phathancharoen, deputy national police spokesman, told Reuters. "We basically sent in the modus operandi [of the suspect] and also the appearance of the suspect we're looking for."

Thai authorities reportedly said Thursday that the bombing was not related to international terrorism. 

On Wednesday, investigators released a sketch of the suspected bomber and issued an arrest warrant against him. Police also released surveillance footage, a day after the deadly bombing, claiming that a man dressed in a yellow T-shirt carrying a backpack as seen in the video was the bomber. They were, however, unsure if the man was still in the country.

Channel News Asia, citing police, tweeted a grainy photo Thursday, reporting that two men dressed in red and white were also suspects.

Thailand will offer a 1 million baht reward ($28,104) for information on suspects of the Bangkok bombing, police spokesman Lt. Gen. Prawut Thavornsiri announced Wednesday on Twitter. Earlier in the day, Thai Prime Minister Prayuth Chan-ocha urged the suspect to surrender.

“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," he said, adding: "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."

The Hindu shrine, located in Pathum Wan district, was built in 1956 and is a popular tourist attraction.