Greta Thunberg and 11 other activists set out to protest Israel’s military campaign in Gaza carrying relief aids, arrived at an Israeli port Monday after Israeli forces stopped and detained them

The Freedom Flotilla Coalition, which organized the voyage, said the activists were “kidnapped by Israeli forces” while trying to deliver desperately needed relief materials.

The boat, accompanied by Israel’s navy, arrived in Ashdod in the evening, according to Israel’s Foreign Ministry. It published a photo on social media of Thunberg after disembarking.

The 12 activists were undergoing medical checks to ensure they are in good health, the ministry said. They were expected to be held at a detention facility in Ramle before being deported, according to Adalah, a legal rights group representing them.

“The ship was unlawfully boarded, its unarmed civilian crew abducted and its life-saving cargo — including baby formula, food and medical supplies — confiscated,” it said in a statement.

It said the ship was seized in international waters about 200 kilometers (120 miles) from Gaza, and Adalah asserted that Israel had “no legal authority” to take it over.

Israel’s Foreign Ministry portrayed the voyage as a public relations stunt, saying on social media that “the ‘selfie yacht’ of the ‘celebrities’ is safely making its way to the shores of Israel.”

It said the activists would return to their home countries and the aid would be sent to Gaza through established channels. It circulated footage of what appeared to be Israeli military personnel handing out sandwiches and water to the activists, who were wearing life vests.

Israeli officials said the flotilla carried what amounted to less than a truckload of aid.

“This wasn’t humanitarian aid. It’s Instagram activism,” Israeli government spokesperson David Mencer said. “Meanwhile, Israel has delivered over 1,200 truckloads in the last two weeks. So who’s really feeding Gaza and who’s really feeding their own ego? Greta was not bringing aid, she was bringing herself.”

The Madleen set sail from Sicily a week ago. Along the way, it stopped on Thursday to rescue four migrants who had jumped overboard to avoid being detained by Libya’a coast guard.

“I urge all my friends, family and comrades to put pressure on the Swedish government to release me and the others as soon as possible,” Thunberg said in a prerecorded message released after the ship was halted.

Adalah, the rights group, said in a statement that “the arrest of the unarmed activists, who operated in a civilian manner to provide humanitarian aid, amounts to a serious breach of international law.”