Eight crew members of a Greek-flagged tanker ship that were kidnapped by pirates off the coast of Cameroon in December have been freed, Greece's merchant marine ministry said Wednesday.

The Happy Lady Tanker crew were abducted by gunmen on December 31, and were held in captivity for more than 20 days.

The gunmen stormed into the tanker as it was trying to anchor two nautical miles (2.3 miles, 3.7 kilometers) outside the port of Limboh.

The ministry said the eight, including five Greeks, had been freed in the early hours of Wednesday after "the successful end of negotiations."

The five Greeks were in good health and were taken to a safe location as they await to return home.

There has been a spike in the number of incidents of piracy in the Gulf of Guinea, with a recent report by the International Maritime Bureau noting a 50% increase in piracy in the area last year. The region accounted for more than 90% of global crew member kidnappings in 2019. The Greek merchant fleet is one of the largest in the world and several incidents have involved Greek owned or flagged ships.