Manila: A nationalist group on Wednesday accused an American submarine of violating the country's law banning nuclear weapons as the vessel docked at a former US Navy base northwest of the capital on Tuesday.

The Bagong Alyansang Makabayan (New Nationalists Alliance or Bayan) in a statement, said the presence of the USS North Carolina in the country's waters may be a violation of a provision of the Philippines' Constitution.

"The Philippines is de facto hosting US warships presumably armed with nuclear and other weapons of mass destruction. The entry of the nuclear submarine may be in contravention of the Philippine constitutional ban on nuclear weapons," Bayan secretary-general Renato M. Reyes, Jr said.

"Article II, Section 8 of the Philippine Constitution states that the Philippines, consistent with the national interest, adopts and pursues a policy of freedom from nuclear weapons in its territory," he said.

The submarine dropped anchor on Tuesday in Subic, Zambales — the biggest US naval base outside America until 1993.

Subic is just 120 nautical miles away from the Scarborough Shoal the current bone of contention between the Philippine and China. Naval forces of the two countries have been on guard since last month when the Phillipine Navy ship accosted four Chinese vessels for intruding the country's territorial waters.

The submarines' presence in the country, according to Philippine Navy spokesman Lieutenant Colonel Omar Tonsay, is part of "routine ship replenishment," of supplies.