Israeli forces are intercepting a flotilla of more than 50 boats carrying aid for Gaza in international waters west of Cyprus, according to pro-Palestinian activists.

The Global Sumud Flotilla says its fleet was being boarded in what it called an illegal act of piracy about 250 nautical miles from Gaza, which is under an Israeli maritime blockade. A live video stream showed armed commandos climbing onto several boats.

There was no immediate comment from Israel. Earlier, its foreign ministry described the flotilla as "a provocation for the sake of provocation" and said it involved "two violent Turkish groups."

Last month, Israeli forces intercepted 22 boats from the same flotilla near Crete. About 175 activists were detained, most released the next day following international condemnation. Two activists-Saif Abu Keshek of Spain and Thiago Ávila of Brazil-were taken to Israel, detained for 10 days, then deported.

The remaining boats sailed to Marmaris, Turkey, where about 50 departed last Thursday heading toward Gaza. Activists say they must deliver aid to Palestinians in dire conditions, with 2.1 million people displaced despite a seven-month ceasefire.

Israel insists the maritime blockade is lawful and says Gaza is "flooded with aid." The UN reports that only 86% of approved humanitarian supplies are offloaded; the rest are returned.