A Russian spacecraft carrying supplies was docked manually at the International Space Station early Saturday after its navigation system failed, officials said.

The unmanned Progress M-21M space freighter carried more than 2.7 tons of food, fuel, experiment hardware and other supplies to the ISS's six Expedition 38 crew members, RIA Novosti reported.

Vladimir Solovyov, flight director of the Russian segment of the ISS, said the docking had to be carried out manually because the spacecraft's new navigation system -- called Kurs-NA -- malfunctioned. No other information on the situation was reported.

The Kurs-NA system is fully digital and, when working properly, should allow spacecrafts to dock with better precision than those with the previous version of the system, called Kurs, Russian space officials have said.