GAZA CITY (Ma'an) -- Israeli forces on Tuesday detained fishermen working off the coast of the Gaza Strip.

Local official Mahfouth al-Kabareeti told Ma'an that Israeli naval forces detained Nader Yousef Abu Simaan, 22, and his brother Hasan at sea and confiscated their equipment. The brothers, from al-Shati refugee camp, were fishing within the area designated by Israel, he added.

An Israeli military spokeswoman said forces detained fishermen from Gaza because they deviated from the designated fishing area.

They were transferred to the custody of security forces, she said. She could not immediately specify how many fishermen were detained.

Israeli and Palestinian negotiators agreed on a 20-nautical-mile fishing zone off Gaza's coast under the Oslo Accords, but Israel unilaterally imposes a 3-mile limit. Israeli warships frequently open fire at boats that allegedly stray from the permitted area.

Fishermen say the limits have destroyed their livelihood and that it is impossible to trawl a large catch within the designated area.

Israel has controlled Gaza waters since its occupation of the area in 1967, and has kept several warships stationed off the coast since 2008.