The fleet of pro-Palestinian activist boats attempting to break Israel's naval blockade of Gaza have been intercepted by the Israeli navy.
The activists on board the flotilla reported seeing Israeli naval vessels about 8pm, local time, when they were around 70 to 80 nautical miles west of Gaza, before troops began boarding some of the 49 vessels in the convoy.
The boat carrying Swedish climate activist Greta Thunberg was the first to be boarded and video posted by the Israel Foreign Ministry appeared to show her detained.
The flotilla said Israeli navy forces were using "active aggression" on their fleet.
"Florida vessel has been deliberately rammed at sea. Yulara, Meteque and others have been targeted with water cannons," the Global Sumud Flotilla said in a post on Telegram.
All passengers on board are unharmed, the Global Sumud Flotilla said.
The Israeli Ministry of Foreign Affairs released a video showing a junior naval officer speaking to the flotilla via radio, instructing vessels to change course from Gaza and head to Ashdod port.
Israel offered to offload the symbolic shipments of aid carried by the flotilla and deliver them to Gaza.
The foreign ministry said, "several vessels of the Hamas-Sumud flotilla have been safely stopped and their passengers are being transferred to an Israeli port".
"Greta and her friends are safe and healthy," it said in a post on X.
The ministry earlier said the navy had warned the flotilla it was approaching an active combat zone and violating a lawful blockade, and asked it to change course.
It said that it reiterated the offer to transfer any aid peacefully through safe channels to Gaza.
The flotilla vessels responded by saying Israel's naval blockade was illegal and they would continue to Gaza.
Activists on board the boats reported Israel naval vessels shining bright lights and spraying water on their decks prior to sending boarding parties.
The activists are expected to be detained and then taken to Ashdod, where they will be told to sign deportation orders and flown out of the country.
Those who don't will likely appear before an Israel tribunal before being deported.
The flotilla was carrying small quantities of aid and said its intention was to break Israel's siege of Gaza and highlight the plight of Palestinians.
Israel maintains its blockade is legal and alleged the activist organisations have links to the militant group Hamas, something they vehemently deny.
Türkiye's Foreign Affairs Ministry accused Israel of "an act of terrorism" by intercepting the activist flotilla bound for Gaza.
"The attack by Israeli forces in international waters against the Global Sumud flotilla, which was on its way to deliver humanitarian aid to the people of Gaza, is an act of terrorism that constitutes the most serious violation of international law and endangers the lives of innocent civilians," the ministry said in a statement.
Six Australians on board
The Global Sumud Flotilla (GSF) is an international initiative aimed at breaking Israel's blockade of Gaza and delivering humanitarian supplies to the Palestinian people.
The fleet of more than 40 vessels, carrying people from at least 44 countries, set sail from Barcelona on August 31.
The flotilla is carrying almost 500 people, including parliamentarians, lawyers, humanitarians, doctors and Ms Thunberg.
Six Australians are on board, including Bianca Webb-Pullman, Daniel Coward, Surya McEwan, Juliet Lamont, Hamish Paterson and Abubakir Rafiq.
Australia's assistant minister for foreign affairs and trade, Matt Thistlethwaite, said he was "deeply concerned" about the risks to the safety of passengers onboard, in anticipation the boats would be intercepted by Israeli forces.
"Australia calls on all parties to respect international law and international humanitarian law, and to refrain from any unlawful or violent act against the Flotilla," he said in a statement released ahead of the IDF's interception.
Government officials have made representations to the Israeli government over concerns Australians would be detained or arrested.
It also made representations to countries including Spain, Italy and Greece to seek their support for Australians on board.
Mr Thistlethwaite said the government was ready to provide consular assistance to Australians onboard.
"We understand people are distressed and want to respond to the humanitarian catastrophe in Gaza — we also want to see critical aid being delivered," he said.
"However, we are very concerned about the safety of these people, including Australians."
ABC/wires