The Polnocny (or Polnochny)-class ships are amphibious warfare vessels. They were designed in Poland, in cooperation with the Soviet Navy and were built in Poland between 1967 and 2002. They now serve in several different navies, and some have been converted to civilian use. The name comes from the Stocznia Północna shipyard (Northern Shipyard) at Gdańsk, where they were built. 107 were built by 1986 (last 16 by Stocznia Marynarki Wojennej (Naval Shipyard) at Gdynia, Poland). In 2002, one ship of a modernised design NS-722 was built in Gdynia for Yemen.