THE HAGUE — Angry Dutch citizens on Thursday asked their country's highest court to put an immediate end to natural gas production in the Groningen region due to the risk of earthquakes.

Once Europe's largest gas field, decades of extraction have led to dozens of minor tremors every year, damaging thousands of homes and sparking unrest among locals and prompting authorities to impose caps on activity at Groningen.

"Seismic risks are still increasing, all we hear are promises of future improvements, but nothing's really happening", resident and politician Nette Kruzenga said in court.

An unusually severe magnitude 3.4 quake prompted the Dutch government last year to pledge to end production by 2030 and to lower it as quickly as possible in coming years.

Groningen is run by NAM, a 50-50 joint venture between Royal Dutch Shell and Exxon Mobil.

Output is set to drop to 19.4 billion cubic meters (bcm) in the year that began in October, down from a 2013 peak of 54 bcm. It will be cut by another 75 percent in the next five years, the government has said.

"Production has already been lowered to the lowest possible level", state lawyer Hans Besselink said in court on Thursday. "Further reductions would lead to shortages at companies in the Netherlands and abroad."

But many in the region still feel their safety concerns are being ignored, as tremors are expected to continue, while numerous attempts to set up a compensation scheme for damage and repairs have failed.

The petitioners demand drilling be stopped immediately, or at least capped at 12 bcm per year, a level the Dutch gas regulator last year said would limit risks.

"We need two to three years to get at 12 bcm, it's impossible to reach it straight away without disrupting consequences," Besselink said .

The government expects the 12 bcm level might be reached by the end of 2020, by switching large industrial users away from Groningen gas and by building extra capacity to convert high-caloric imported gas to the low-caloric gas needed for the Dutch network.

The Netherlands still depends on Groningen gas for a significant part of its energy supply and export obligations.

The High Court in 2017 said certainty of supply should play a role in decisions on the production level, but should not outweigh safety concerns.

The court expects to deliver its verdict on Jan. 31. It will also hear 26 other complaints from local authorities and interest groups in April. — Reuters