An earthquake in Helensburgh "felt like a lorry crashing into the side of a house".

The 2.4 magnitude quake hit the Firth of Clyde just north of Greenock on Thursday night and could be felt in Dunoon, Greenock, Helensburgh, Gourock and surrounding villages.

The tremor was recorded by the British Geological Survey's seismometer at 11.34pm.

Local residents contacted the BGS to say their windows shook, doors rattled and ground rumbled, with one saying it "felt like a lorry crashing into the side of their house".

However, there have been no reports of damage to property.

David Galloway, a local seismologist from the BGS said: "We received around 20 calls reporting a small earthquake on the Firth of Clyde north of Greenock.

"Around 30 people have responded to a questionnaire on our website detailing their experiences."

The BGS monitor 100 seismometers throughout the UK - it said that if anything above background noise is detected they can determine whether or not it is an earthquake.

Thursday's quake was the third to hit Scotland this month with a 2.3 magnitude tremor recorded near the North Sea in Aberdeen.

There are around 250 earthquakes in Britain every year but most go unnoticed.

In 1880 a 5.2 magnitude earthquake near Loch Awe is the largest ever recorded in Scotland.