Israeli military forces on Wednesday intercepted a flotilla of ships trying to break the naval blockade of Gaza, according to the Israeli Foreign Ministry and to a legal defense group representing the activists aboard.

Israel detained the more than 140 activists on the flotilla, according to Adalah, the legal defense group.

Israeli forces stopped the ships at about 4:30 a.m. local time some 120 nautical miles from Gaza, well into international waters, said Miriam Azem, a spokeswoman for Adalah. The activists were being taken to Israel for deportation, the Israeli Foreign Ministry said.

The flotilla was the latest effort by pro-Palestinian activists to breach the Israeli sea blockade of the Gaza Strip. They call the measure an illegal collective punishment of Palestinian civilians. Israel has said it considers the blockade legitimate military action.

Last week, Israel detained more than 400 activists from around the world — including Greta Thunberg, the Swedish climate campaigner — who had sought to reach the Gaza coast in dozens of ships. The detainees included about 20 Americans.

Israeli forces intercepted the ships, and most of the detained activists had been deported as of Wednesday, except for seven who remain in Israeli detention, said Ms. Azem, whose group also represents those activists.

Israel’s conduct of the war in Gaza, now in its third year, has prompted a surge in pro-Palestinian sentiment in many European countries and in the United States, where support for Israel has dropped precipitously.

Israel’s military campaign against Hamas has killed more than 67,000 people in Gaza, including thousands of children, according to Gaza health officials, who do not distinguish between civilians and combatants. The Hamas-led attack on Israeli on Oct. 7, 2023, that precipitated the war killed about 1,200 people and saw another 250 taken as hostages.

Palestinians in Gaza have endured a nightmarish two years of hunger, displacement and bombardment. United Nations officials and aid groups say that Israeli policies have led to widespread hunger and even pockets of famine in Gaza, a charge that Israel has denied.

After the widely publicized flotilla carrying Ms. Thunberg and the other activists was intercepted last week, protests broke out in Italy and in several other countries.

Ms. Azem, the Adalah spokeswoman, said that lawyers had met with detainees who said they had been kept on their knees with their hands bound for many hours, held in overcrowded cells and denied adequate drinking water.

The Israeli Foreign Ministry called the allegations of mistreatment “fake news.”