Updated Tuesday 2.25pm

A loud explosion heard in parts of Rabat/Dingli on Monday afternoon was a controlled explosion in a nearby quarry to remove dangerous rocks.

The sound scared residents out of their homes on Monday afternoon.

The police confirmed that they had received many calls reporting the sound at about 5.05pm but at the time they did not know what caused it.  

"It was quite a shock, more like an explosion more than a tremor," one resident said.