European natural gas prices spiked as the Netherlands is set to announce it will close Europe’s biggest gas site later this year.

Benchmark futures soared as much as 24% on Thursday to their highest level since early April. Prices are now jumping for a third consecutive day as prolonged outages and hot weather across the continent spark concern over supplies.

The closure, due earthquake risks near the Groningen gas field, will come into effect from Oct. 1, people familiar with the matter said, speaking on condition of anonymity as the plans are not yet made public. The cabinet will meet to officially decide later this month.