The British government is accusing Spain over what it calls an irresponsible incursion into Gibraltar's waters.

The Foreign Office says a Spanish state research vessel deployed equipment to survey locations within British territorial waters on Sunday.

Europe Minister David Lidington complained to Spain's foreign minister on Monday. Lidington said "the irresponsible actions and dangerous maneuvering of this vessel were not only unlawful but also presented a significant risk to the safety of Royal Navy personnel at sea."

It is the latest in a series of testy incidents over Gibraltar, a territory at the southern tip of the Iberian peninsula that has been British since 1713.

Tensions grew last year after Gibraltar built an artificial reef that Spain says hurts its fishermen. Spain retaliated by beefing up border security, creating delays.