Australian activists who returned to Australia from a Gaza-bound aid flotilla are alleging they were subjected to severe mistreatment during detention following the interception of their vessel in international waters last week, according to local media reports.

The claims, which include allegations of physical abuse, sexual violence, denial of medical care and degrading treatment, are being made by multiple members of the group who were part of a larger international delegation attempting to deliver humanitarian supplies to Gaza, SBS News reported.

Eleven Australians were among hundreds of activists aboard the Global Sumud Flotilla when it was intercepted by Israeli forces in international waters, according to Australian media. The activists were detained and later released in stages, with the first group arriving home over the weekend and more returning on Monday through Melbourne Airport.

In interviews with Australian broadcasters, several returnees described what they said were violent and prolonged conditions in custody. Allegations included beatings, the use of tasers, and injuries such as broken bones and head trauma. Some activists also claimed detainees were injected with unknown substances while held in detention.