JERUSALEM, July 29, 2025 (BSS/AFP) - More than a dozen activists being held by Israel after their aid boat was intercepted en route to Gaza launched a hunger strike on Monday to protest their detention, according to a local NGO assisting them.

At least five of the 21 passengers of the Freedom Flotilla vessel Handala have agreed to be summarily deported after the boat was stopped and boarded by the Israeli navy while attempting to break a military blockade of the war-ravaged Palestinian territory.

The legal aid group Adalah said that on Monday afternoon, "hearings concluded at Givon Prison, concerning the continued detention of the 14 volunteers who... refused to consent to an expedited deportation process".

"During the hearings, the volunteers stressed that their mission was humanitarian -- motivated by the need to act against Israel's illegal siege and the genocide against Palestinians in Gaza," the group said in a statement.

One US activist reported "severe physical violence by Israeli forces", while others described being held in poor conditions, Adalah said.

"The activists told the tribunal that they remain on an open hunger strike in protest of their unlawful detention," it added.

It later said the tribunal had "upheld the continued detention of the 14 volunteers".

Israel has been treating their cases as immigration violations, which Adalah maintains is illegal, saying they were brought into the country against their will from international waters.

The Handala's 21 passengers hailed from 10 countries, and included two French lawmakers and a pair of Al Jazeera journalists.

Adalah said at least one of the lawmakers, the two journalists and two other passengers were already on their way out of the country.

Two passengers who were Israeli-American dual nationals were released after being interrogated, according to the organisation.

A previous boat sent by Freedom Flotilla, the Madleen, was also intercepted by the Israeli military in international waters on June 9.

It carried 12 campaigners, including prominent Swedish activist Greta Thunberg. The activists were eventually expelled by Israel.