TUNIS, Tunisia (AP) — Tunisian authorities detained several pro-Palestinian activists Friday as tensions mounted around an international campaign preparing a new humanitarian flotilla to challenge Israeli restrictions and bring aid to Gaza, organizers said in a statement.

Tunisian media reported that Tunisia’s National Guard financial crimes unit opened an inquiry into suspected money laundering, fraud and the alleged misuse of funds collected through donations to the flotilla campaign.

The probe reportedly targets several managers and members of the flotilla steering committee, with certain members taken into custody as authorities verify the origin and management of donation funds. Tunisian authorities didn't publicly comment on the detentions.

Activists said police detained Wael Naouar, Jawaher Channa and Nabil Channoufi, of the Global Sumud Flotilla steering committee and its Tunisian organizing body. None of the detained has commented.

Organizers accused authorities of targeting activists supporting the Palestinian cause and called for their immediate release.

The detentions followed several days of disruptions to flotilla-related events in Tunis linked to preparations for a new civilian mission seeking to sail toward Gaza. Israel intercepted boats and detained activists on a similar flotilla effort last year.

The United Nations said that hundreds of thousands of pallets of humanitarian supplies have been collected at various crossings into Gaza since a fragile ceasefire in October. But Israel has suspended more than two dozen humanitarian organizations from operating in the Gaza Strip for failing to comply with new registration rules and Gaza's population of over 2 million Palestinians still face a humanitarian crisis.

According to organizers, the new flotilla is to include more than 1,000 activists including medical doctors, war crimes investigators and engineers. It will be supported by a land convoy that is expected to attract thousands more. The boats are expected to sail from Spain, Tunisia and Italy.

Authorities banned a planned event Thursday in Tunis that had been expected to host international activists including Brazilian campaigner Thiago vila, Swedish climate activist Greta Thunberg and Global March to Gaza Palestinian organizer Seif Abu Koshk.

vila's team said on Facebook that he was also detained Friday at Brussels Airport while traveling from Tunis to Amsterdam for a meeting of the Hague Group, a bloc of states committed to legal and diplomatic measures in defense of international law.

Earlier this week, activists said security forces prevented a ceremony at the Tunisian port of Sidi Bou Said intended to honor port workers who had supported the previous flotilla mission last year.

Prior to Friday’s arrests, the Tunisian branch of the flotilla’s steering committee had also called for a protest in Tunis on Saturday night in support of Iran following joint strikes by the United States and Israel.