Iceland has declared a state of emergency after thousands of tremors raised fears of a volcanic eruption.

Authorities have ordered thousands living in the southwestern town of Grindavik to evacuate as a precaution and have closed the nearby Blue Lagoon tourist attraction.

The area around Mount Thorbjorn on the Reykjanes Peninsula has been shaken by hundreds of small earthquakes every day for more than two weeks due to a build-up of volcanic magma - molten rock - around three miles (5km) underground.

Land in the region has risen by 9cm (3.5in) since the end of October, according to the Icelandic Met Office (IMO).

Scientists are closely monitoring the situation for any indication the seismic activity is getting closer to the surface.

The most disruptive in recent times was the 2010 eruption of the Eyjafjallajokull volcano, which spewed huge clouds of ash into the atmosphere and led to widespread airspace closures over Europe.

The Reykjanes Peninsula on Iceland's southwestern coast includes a volcanic system that has erupted three times since 2021, after being dormant for 800 years.

The evacuation of Grindavik came after the IMO warned "significant changes have occurred in the seismic activity" and that magma could have extended under the town, which is located about 33 miles (53km) from the capital Reykjavik.

The IMO said: "At this stage, it is not possible to determine exactly whether and where magma might reach the surface."

Iceland's civil protection agency ordered residents to leave the area but stressed it was not an emergency evacuation. It said there was "plenty of time to prepare... and drive out of town calmly".

"There is no immediate danger imminent, the evacuation is primarily preventive," the agency added.