The two - the Ukrainian captain of the Perseus and its Greek first engineer - were released on Friday morning, the Merchant Marine Ministry said. They had been kidnapped in a Jan. 26 attack on the Perseus, which had been moored off the port of Onne waiting to load up with cargo. Two Egyptian sailors were wounded in the attack.
The ministry said the two released officers are at a naval base in Nigeria and will be undergoing medical checks before returning home, possibly on Sunday.
The St. Vincent and Grenadines-flagged Perseus had a crew of 15 Ukrainian, Greek, Syrian, Egyptian and Filipino seamen.
Greece is a major shipping power, with Greeks controlling nearly 20 percent of the world's merchant fleet. Shipping has become increasingly risky, with pirates frequently targeting cargo and tanker ships, mostly off the east coast of Africa near Somalia, and in the waters near Nigeria.
On Wednesday, pirates captured a Greek-flagged supertanker sailing off the coast of Oman with a cargo of 266,000 tons of crude oil and a crew of seven Greeks, 17 Filipinos and one Georgian. The previous day, Somali pirates firing small arms and rocket-propelled grenades hijacked an Italian-flagged oil tanker in the Indian Ocean.