Police spokesman Pol Lt Manoj Plodkhanngern said the explosions occurred at 12.10pm.
The first two bombs were put in two lubricant cans which were laid near a trash bin at Long Gong circle behind Tanyongmat railway station.
The third was placed at an electricity pole in front of the Bank for Agriculture and Agricultural Cooperatives.
The fourth bomb was placed at the clock tower in front of the Tanyongmat railway station.
The bombs were detonated simultaneously, but the explosions caused no damage or casualties.