Lawyer of suspect says he committed the act to repay a 'personal favour'.
The mastermind behind the fatal bomb blast in Bangkok had arrived in Bangladesh a day before the August 17 blast and left for China after two weeks, police says.
Thai police say a key suspect in the Bangkok shrine bombing has confessed to giving a bag containing a device to the man who carried out the attack.
Thai police say they have found bomb-making materials in a second apartment, after the arrest of a suspect in the explosion at Bangkok's Erawan Shrine.
Thai police say the trail had gone cold in the hunt for a bomber a week after 20 people were killed in the country's worst bomb attack.
Thai police on Saturday said they were investigating new security camera footage showing a man dropping a package into a canal.
The authorities believe that bomb blasts at the Erawan shrine and Sathorn Bridge in Bangkok this week were aimed at discrediting the military government in Thailand, national police chief General Somyot Poompanmuang says.
Monday's bombing in Thailand "unlikely" to be the work of international terror group, Thai government says.