Three crew members have been hospitalised in Valencia, Spain, after a Covid-19 outbreak on two containerships in the port.

A total of 13 positive tests have been recorded on AP Moller-Maersk's 4,650-teu Maersk Utah (built 2006) and Marfret's 6,881-teu Skiathos I (built 2013).

The ships arrived in the port on 1 May, with both managers reporting cases of coronavirus to the authorities.

It is not clear which vessels the hospitalised seafarers are from. Two were admitted in the week ending 7 May and another more recently.

The latest admission was to a private hospital in the city, the ministry of health said.

The ministry has not been able to identify which variant is responsible.

Earlier, another seafarer developed a fever and was taken to hospital.

Remaining in quarantine

Seven crew members from Skiathos I remain in quarantine, and six from the Maersk vessel, which had arrived from Algeciras in Spain, the ministry said.

Skiathos I had arrived from Barcelona.

Maersk told TradeWinds that 10 crew members have been isolated on the vessel. Tests have revealed nine positives and one negative test.

"They are all stable and getting better and they are under daily medical supervision of the captain and our doctor," a spokeswoman said.

Valencia Port Authority ordered the vessels to dock away from the main shipping channels.

The latest wave of Covid-19 is proving more dangerous to seafarers than earlier phases of the pandemic.

On 10 May, TradeWinds reported that two crew members were in intensive care in a French hospital after an outbreak of Covid-19 on a State Oil Company of the Azerbaijan Republic (Socar) tanker.

The 14,400-dwt FMT Bergama (built 2009) had been in quarantine since 8 May after 12 seafarers tested positive at Port-la-Nouvelle.

The vessel had arrived from Terneuzen in the Netherlands, having left on 28 April.

In April, the body of a crew member was found on a beach in Vanuatu.

Unexplained death

The seafarer from BW Epic Kosan's 3,678-cbm LPG carrier Inge Kosan (built 2011) was later found to have Covid-19, but a cause of death has not been established.

Earlier that month, a Greek bulker was quarantined in Crete after a crewman was found dead in his cabin, while 10 others later tested positive for Covid-19.

The seafarer was discovered on the 182,000-dwt Heroic (built 2010), owned by CM Lemos company Nereus Shipping, Greece's Hellenic Coast Guard said.

And two seafarers died as Brazil's dire Covid-19 emergency spread to three vessels.