Tel Aviv: Israel has placed two international activists from a Gaza-bound aid ship in solitary confinement, an Israeli rights group said on Wednesday.

According to Anadolu Agency, the rights organization and legal center Adalah reported that Brazilian volunteer Thiago Avila and French-Palestinian European Parliament member Rima Hassan were transferred to separate prison facilities and placed in solitary confinement.

Adalah's statement highlighted that Thiago Avila was isolated in Ayalon Prison due to his ongoing hunger and thirst strike, initiated two days prior. The rights group mentioned that while Avila has faced aggressive treatment from prison authorities, it has not reached the level of physical assault.

Meanwhile, Rima Hassan was placed in isolation under adverse conditions in Neve Tirza Prison after writing 'Free Palestine' on a wall in Givon Prison. She was reportedly moved to a small, windowless cell with poor hygienic conditions and denied access to the prison yard.

The rights organization condemned the transfer of the two activists as a violation of their rights and an effort to apply mental and political pressure. Adalah called on Israeli authorities to cease the solitary confinement, stop all retaliatory measures, and release all detained volunteers.

Later, it was reported that Rima Hassan was moved from solitary confinement back to Givon, while Thiago Avila remains in solitary.

The activists were among 12 international volunteers detained by Israeli forces aboard the Madleen aid ship on Monday. Four activists, including Swedish climate activist Greta Thunberg, were deported to their home countries on Tuesday. The remaining activists in Israeli custody include individuals from Trkiye, the Netherlands, France, and Germany.

The British-flagged vessel was intercepted by Israeli forces in international waters as it attempted to breach the Israeli naval blockade on Gaza. This comes amid a deadly onslaught in Gaza since October 2023, which has resulted in over 55,100 casualties. Aid agencies have raised alarms over potential famine among Gaza's 2.4 million residents, as Israel has continued to block humanitarian aid since early March.

In a related development, last November, the International Criminal Court issued arrest warrants for Israeli Prime Minister Benjamin Netanyahu and former Defense Minister Yoav Gallant for alleged war crimes and crimes against humanity in Gaza.