Thai police announced the suspect, who was arrested last week, has confessed to possessing banned explosives.

According to CNN, Yusufu Meerailee confessed to the crime after being arrested last week near the Cambodian border. He was carrying a piece of paper with a chemical formula on it.

"We have informed him (Yusufu) of the charge of jointly possessing and owning explosives that are banned by the government. He acknowledged the charge and confessed (to it)," National Police spokesman Prawut Thavonsiri told reporters at a news conference on Monday. It was revealed later that Yusufu was the one responsible for making the bombs.

Both Yusufu and fellow suspect Adam Karadak were arrested on the same day in connection to the bombing. Yusufu's fingerprints were also discovered on the bomb-making materials, police stated.

Police also announced that they issued additional arrest warrants for suspects, who are wanted for the bombing last month that killed 20 people and injured over 100 people.

According to the Hindustan Times, two Indians were taken into custody after they were seen talking to the main suspect minutes before the explosion. The two were later questioned and released. The two Indians were living next door to the room where bomb-making materials were found.

Thai police are looking for two more suspects, whose names were released last week: Emrah Davutoglu and Wanna Suansan, husband and wife. Police believe that they may have left the country. Suansan is a person of interest after police found explosive materials in her house.

Suansan's mother was interviewed by the police and said that her daughter fled to Turkey.

Suansan contacted the police via social media and declared her innocence.

So far, no one has been charged with any crime, although police holds many suspects in connection to the bombing.