A lifeboat from a British-operated cruise ship fell upside down into the sea at port in Spain's Canary Islands during a safety drill, killing five crew members and injuring three others Sunday, officials said.

About 1,400 passengers were on board, but none were involved in the accident.

Thomson Cruises confirmed the incident involving the Thomson Majesty ship on the island of La Palma, saying "there have sadly been five crew fatalities and three crew injuries."

"One person has been discharged from hospital and we expect the other two people to be released from hospital imminently," the British company said in a statement. "Our thoughts are with the families of those involved."

The Thomson Majesty was docked in La Palma, Canary Islands at the time of the incident. (Google Map)

Investigators were trying to determine what caused the lifeboat to plummet into the water.

Rescue personnel were called to the dockside at 1205 GMT after "a lifeboat with occupants had fallen overboard from a cruise ship docked at the pier of Santa Cruz port in La Palma," a regional government statement said.

A small, white two-hulled lifeboat could be seen capsized beside the large ship.

The ship had been due to sail Sunday afternoon to the Portuguese port of Funchal on the mid-Atlantic island of Madeira.

Three of the dead were Indonesian men, one was a Filipino man and another was a man from Ghana, authorities said. The injured were all men, two aged 30 and another, a Greek national, was 32.

The local authorities of La Palma canceled Carnival festivities that had been due to be held on the island Sunday, but said they would go ahead as planned on Monday.