Police in Uganda are using sniffer dogs to look for more evidence and detect any explosives at the scenes of the blasts in the centre of the capital, Kampala.
One went off near the central police station which is also close to parliament.
The Daily Monitor newspaper shared photos of the operation Major Gen. Abel Kandiho, the Chief of Military Intelligence (CMI) and other security officials have arrived at the scene.
Security officials have increased surveillance across the city, NTV Uganda reports.
The Daily Monitor is reporting that parliament has been suspended.