The pipe bomb found near Thailand Cultural Centre subway station is not linked to three recent bombings in Bangkok, but the device is similar to explosive devices used in two bombings in 2014 and 2015.
The device found in rubble behind a restaurant near the MRT subway station is similar to the devices used in two explosions in the Minburi area and at the BTS skytrain station at Siam Square.
According to the Explosive Ordnance Disposal (EOD) chief Pol Col Kamthon Ouicharoen, the bomb is a metal pipe with lit fuse and gun powder inside.
There are no ball bearings or nails inside, he said.
But he added that if the bomb exploded , it could cause death and serious injuries because the metal pipe itself would turn into shrapnel.
From the condition of the bomb device, he said it had been left in the rubble for over a month.
He said the explosive device found is similar to the bomb device which exploded on March 27, 2014 in Minburi and at BTS Siam skytrain station on February 1, 2015.
Police had arrested several suspects in the Minburi explosion and they turned out to be those with different political ideology.