Australian officials are evacuating workers from a Kuwaiti-flagged livestock ship docked off the country’s west coast after at least half the 52 crew tested positive for Covid-19.

The West Australian government said 24 of the crew had tested positive since the ship arrived in Australia last week. The remainder have been tested and are awaiting results. Two Australian crew members left the ship before the outbreak was detected, but had since tested negative, officials said.

“It is becoming clear that ships arriving with Covid-19 on board is one of the weakest links and the biggest risk to our way of life in Western Australia,” state Premier Mark McGowan told reporters in Perth.