Spain's government pointed Friday to a likely connection between numerous low-magnitude temblors along the country's Mediterranean coast and injections of natural gas into a large offshore storage facility.

Experts have reached the preliminary conclusion that there is a "high probability of a direct relationship" between the gas injections into the Castor storage plant and seismic movements, Industry, Energy and Tourism Minister Jose Manuel Soria said.

The minister said gas injections would remain suspended and not be resumed until sufficient safety guarantees are in place.

Soria made his remarks at a press conference after the regular Friday Cabinet meeting, saying that the expert report indicated that "significant" but "limited" seismic activity associated with Castor - located off the coast of the eastern Spanish town of Vinaros - had been detected.

More than 300 seismic movements have been registered in the region, the strongest a magnitude-4.2.

The government has commissioned an external audit to verify if the underground gas storage facility's real investment costs are equivalent to those declared by the plant's operator, Escal UGS, Soria said.

The gas storage facility had an initial budget of some 700 million euros ($950 million) but it appears the final cost will exceed that amount, he said.

Soria did not indicate if the government would need to compensate Spanish firm Escal UGS for canceling its concession if that were to occur.

The aim of the 1.2-billion-euro ($1.63-billion) Castor project is to use a depleted oil reservoir 1,750 meters (5,735 feet) below sea level to store enough imported natural gas to cover a third of Spain's gas needs for 50 days, and thus keep prices stable. EFE