MOSCOW, Russia (CNN) -- Crew members from a hijacked Russian ship landed in Moscow on Thursday, nearly a month after it was commandeered off the coast of Finland.
The Arctic Sea was found by a Russian Navy vessel on Monday.
"Eleven members of the crew from the dry cargo vessel Arctic Sea ... arrived in Moscow" from Cape Verde, the Russian Foreign Ministry said in a statement.
"Four crew members, led by the captain, remain on duty aboard the ship. The physical, moral and psychological conditions of all our sailors are good," the ministry added.
Eight hijacking suspects -- from Estonia, Latvia and Russia -- arrived soon after, Russian state TV showed. They could be seen getting off a plane in handcuffs.
The Russian navy took the Arctic Sea back from hijackers on Monday without firing a shot. At the time, the ship was about 300 miles (480 km) from Cape Verde, an island nation a few hundred miles from the coast of western Africa. The 15-man crew was unharmed.
Russian authorities have opened a criminal investigation into the case, the Prosecutor General's Office said Tuesday.
The Arctic Sea, which was sailing under a Maltese flag, had not been heard from since July 31. It was carrying 6,500 tons of timber from Finland to Algeria when it reported trouble on July 24 off Finland.
The crew had told authorities that eight to 12 people with guns boarded the vessel about 3 a.m. that day, masked and wearing uniforms with "police" written on them, the Malta Maritime Authority said.
CNN's Michael Sefanov contributed to this report.