A Danish containership has been robbed by three raiders in West Africa as crew mustered in the citadel.

Navigare Capital's 3,508-teu Niledutch Breda (built 2014) was anchored six nautical miles (11 km) off Pointe-Noire in the Republic of the Congo when the incident took place in the early hours of Monday.

Three intruders were seen on the Cyprus-flag panamax's forecastle, according to security consultancy Ambrey.

They escaped in a long wooden boat with two stolen mooring lines. No injuries to crew have been reported.

At the time, the boxship had an estimated 6.8-metre freeboard.

Local authorities were informed of the incident and sent a patrol boat to investigate. No arrests were reported.

The ship has remained anchored at Pointe-Noire, according to AIS data.

Navigare Capital has been contacted for further information.

The incident was one of two reported on Monday, with an attempted robbery taking place in Morocco.

Seven raiders were removed from a Gram Car Carriers vessel at Casablanca.

Manager OSM of Norway said crew members on the 4,300-ceu Viking Diamond (built 2011) discovered the robbers while the vessel was berthed at the port.

They called in the authorities and the raiders were escorted from the ship, which has since resumed its voyage.

"All Viking Diamond crew are safe and well and we are grateful to the port authority for their assistance," OSM said.