A Covid outbreak has hit a crucial Australian relief ship which was bound for tsunami-stricken Tonga. Some 23 cases of Covid were recorded among the crew of the HMAS Adelaide, which left Australia on Friday. It comes as Tonga is desperately trying to prevent Covid from reaching its shores as more humanitarian aid begins arriving in the Pacific nation. Australia defence minister Peter Dutton has vowed not to put the Tongan population "at risk". The Australian Department of Defence said the HMAS Adelaide would continue making its way to Tonga as planned, and is due to arrive on Wednesday. It said in a statement that it would ensure its supplies were delivered in a "Covid-safe manner". Tonga currently has only had one confirmed Covid case, which was recorded in October 2021. Authorities have stressed the need for aid to be delivered in a contactless way to avoid bringing in the virus. Australia had earlier despatched military transport planes carrying relief supplies, however the HMAS Adelaide vessel is carrying a larger shipment of much-needed aid, including engineering equipment, water and shelter. More than 600 crew are onboard the HMAS Adelaide, which has on board medical facilities including a 40-bed hospital and a critical care ward onboard, said the Department of Defence. This is the second aid shipment from Australia that has been hit with Covid - a C-17 plane had to turn around mid-flight last week after a crew member was diagnosed with the virus. Tonga is reeling from the aftermath of a devastating underwater volcanic eruption that hit the South Pacific island nation several weeks ago. The eruption triggered a tsunami that Nasa estimated was hundreds of times more powerful that the WWII atomic bombs, wreaking widespread devastation and leaving three dead. Officials say four-fifths of the population have been affected by the tsunami and volcanic ashfall, which continues to pose a public health risk to Tonga"s 105,000- strong population. The disasters, and ensuing rescue efforts, have threatened Tonga"s ability to remain Covid-free, with just one case of infection reported last October. Authorities are determined to keep it that away, as the remoteness of some of its island communities, many with limited healthcare resources, makes them particularly vulnerable to an outbreak. — BBC