Two men who have been mentioned in the past few days as possible perpetrators of the bombing in central Bangkok on Monday, have handed themselves in to police on Thursday.

Thai authorities released a video with grainy images of a CCTV surveillance camera showing a young man in yellow shirt carrying a backpack. They pointed to this person as prime suspect and even released a sketch.

However, police also pointed to two other men wearing red and white shirts who appeared on this recording as potential accomplices. Both men handed themselves in to police on Thursday to clarify that they are a tour guide and a Chinese tourist and have no responsibility in the attack, according to the BBC.

Thai police said there are more than one person behind the explosion, and the bomb makers may be foreigners. Authorities also said the suspect who carried out the attack may have already left Thailand.