A South Korean activist is believed to have been detained by the Israeli Navy after it attacked and intercepted the Gaza-bound Global Sumud aid flotilla in the Mediterranean Sea, Yonhap News Agency reported on Tuesday.

According to the aid group, which advocates for Palestinian liberation, the Kyriakos X vessel carrying activist Kim Dong-hyeon was intercepted late on Monday Seoul time by the Israeli Navy near the island of Cyprus.

The flotilla, consisting of more than 50 boats, set sail on Thursday from the Turkish Mediterranean district of Marmaris in a renewed attempt to break the Israeli blockade imposed on Gaza since 2007.

The group said Kim is believed to be detained aboard an Israeli warship along with other international activists.

He departed earlier this month for Gaza as part of the aid flotilla despite a travel ban imposed by the South Korean government on travel to the Palestinian enclave without government approval.

Another activist, Kim Ah-hyun, is reportedly travelling on a nearby vessel that the group warned could also be seized by Israel.

She was detained by Israeli forces during an earlier attempt to enter Gaza in October and was later released.

Organisers said there were 426 people taking part in the mission, among them 96 Turkish activists and participants from 39 other countries including Germany, the US, Argentina, Australia, Bahrain, Brazil, Algeria, Indonesia, Morocco, France, South Africa, the UK, Ireland, Spain, Italy, Canada, Egypt, Pakistan, Tunisia, Oman and New Zealand.

Israeli forces also attacked the Global Sumud aid flotilla off the coast of the Greek island of Crete overnight between April 29 and April 30.