Iceland’s main tourist attraction, Blue Lagoon, will close its operations for at least a week as an underground magma intrusion forming only a few hundred meters away from the geothermal seawater spa is raising the risk of an eruption.

The spa cited “interruption in guest experience” and “strain on staff” as reasons for the shuttering, according to a statement on Thursday. Still, there is presently no sign of an eruption underway, Benedikt Ofeigsson, geophysicist at Iceland’s Met office, said by phone.

Magma keeps accumulating in a horizontal sill at a depth of about 5 kilometers (3.1 miles) and the seismic activity is likely to continue, according to Met Office. The area is about 40 kilometers away from the capital and close to Grindavik, a fishing town of about 3,600 people. An eruption at the site could also threaten a power plant which provides heat for 30,000 inhabitants of the Reykjanes peninsula.

Read More: Iceland’s Top Attraction Blue Lagoon on Alert for Magma Flows