Earth quake in Bambalapitiya?

The Disaster Management Centre states that an investigation has

The residents of the buildings in the area have reported that there was a vibration around 4 a clock.  Investigation are being done to check whether this vibration was as a result of a symptom of an earth quake or it was due to the operations of evacuations made  in the large scale construction work done in the vicinity of the areas where the vibrations of an earthquake was felt by the residents.