Israel shot dead four Palestinian scuba divers off the Gaza coast today, foiling what it said was a terrorist attack.
A naval force spotted them and opened fire, the military said. It refused to give further details of the divers' mission.
The Al-Aqsa Martyrs' Brigades - a violent offshoot of Palestinian President Mahmoud Abbas' Fatah faction - said the divers were members of its marine unit who were training.
Meanwhile today Israel fired a missile at Palestinian militants near the Gaza border, wounding one. It said they were preparing to fire rockets at Israel. The military said 10 rockets and mortars have been fired from Gaza in the past three weeks.
The sea killings came as the repercussions from last week's raid on an aid flotilla that left nine people dead continued to reverberate around the world.
"The bloody escalation today is a desperate attempt by the occupation government to divert the world attention away from the massacre committed against the flotilla," a Hamas spokesman said.
Turkey, an important ally of Israel in the Muslim world, has said it will reduce military and trade ties with Israel and shelved discussions of energy projects. It has also threatened to break ties unless Israel apologises for the raid last week.
Israel's government has been frantically trying to counter the wave of harsh international condemnation that has left it isolated and at odds with some of its closest allies.
Israel has sought to portray the nine killed activists - eight Turks and a 19-year-old boy who held dual Turkish-US citizenship - as terrorists, saying they prepared for the fight before boarding the flotilla. Today it released the names of five of the activists it said have long ties to terror organisations.
The army also said that Gaza's Hamas rulers were preventing the transfer of clothing, blankets and medical equipment from the flotilla that Israel was trying to provide.
Israel has also come under heavy pressure to agree to an international investigation of the raid on the Turkish-flagged Mavi Marmara, the lead ship in the flotilla.