JOHANNESBURG (Reuters) - South Africa ports authority said on Thursday that tests have come back negative for those onboard a cruise liner and cargo vessel which had been held under quarantine off Cape Town’s port limits due to a suspected coronavirus outbreak.

Countries around the world have barred cruise liners from entering their ports, fearful the large ships could fuel the spread of coronavirus similar to the Diamond Princess which was quarantined in Yokohama, near Tokyo, on Feb. 3.

“This means there have to date been no confirmed cases of COVID-19 in any of our ports but we will remain on high alert after this first scare,” said Captain Sabelo Mdlalose, acting chief harbor master at Transnet National Ports Authority.

South Africa held the cruise liner MV AidAmira and the MV Corona cargo vessel after a crew member onboard one of the vessels showed signs of coronavirus.

The cargo vessel left Cape Town on March 11 but the ship’s master contacted port authorities requesting to return on Monday after the patient started to exhibit symptoms of the virus.

The other six passengers on board the Italian-flagged MV AidAmira were quarantined as a precautionary measure for further medical checks, although they did not exhibit any symptoms, Transnet said.

The cruise liner, with 1,240 passengers and 486 crew on board, was on it way back from Namibia’s Walvis Bay. Besides the six, all other passengers and crew remained quarantined on board.

Both vessels have been granted clearance to continue their journeys from Cape Town’s port but it is expected that the cruise liner passengers will be allowed to disembark and fly to their respective countries, Transnet said.

President Cyril Ramaphosa on Sunday declared a state of disaster and implemented urgent measures to fight the pandemic, which has so far affected 116 in South Africa as it spreads rapidly across the continent.