Thousands of animals are packed into ships stuck backed up at the Suez Canal, according to multiple reports, raising alarms about their welfare.

Bloomberg estimates 10 ships stuck in and around the canal are carrying livestock; The Guardian reported that tracking data show that at least 20 ships are transporting animals. Most of the animals are believed to be sheep, but some ships could also be carrying cattle.

The ships now face major delays as the container ship Ever Given remained wedged in Egypts narrow canal Saturday after running aground on Tuesday. Dislodging it may take at least a week.

Ships carrying livestock usually bring enough food and water for just a few extra days, sources told Bloomberg. Then ships either have to head to a port for extra feed, or arrange to have another vessel unload supplies. Ships could also try to sell the animals quickly in a nearby country.

I wouldnt expect just after a two-day delay for a problem to have built up, Peter Stevenson, chief policy officer at animal welfare group Compassion in World Farming , told Bloomberg . Its as time goes by that the problems get worse. Occasionally, there are real scandals when things go wrong, but its a day-to-day horror.

The organization has previously called for an end to live-animal shipments .

Georgios Hatzimanolis, a spokesperson for the tracking website Marine Traffic, told The Guardian that while some livestock ships were waiting to enter the canal, three appear to be stuck at various points in the canal.

Five of the ships identified had loaded animals in Spain, and nine had loaded in Romania earlier this month, according to Animals International .

My greatest fear is that animals run out of food and water and they get stuck on the ships because they cannot be unloaded somewhere else for paperwork reasons, Gerit Weidinger, European Union coordinator for Animals International, told The Guardian.

Getting stuck on board means there is a risk [for the animals] of starvation, dehydration, injuries, waste buildup so they cant lie down, and nor can the crew get rid of dead animal bodies in the [Suez] canal, she said. Its basically a ticking biohazard time bomb for animals and the crew and any person involved.

The U.S. has offered to aid efforts to move the Ever Given to open the canal. Several incoming vessels are now being diverted around Africas Cape of Good Hope, and dredging vessels are working around the clock to dislodge the massive ship.