JERUSALEM: About 15 people were killed on Monday when the Israeli navy intercepted a convoy of aid ships that activists were trying to sail to the Gaza Strip, Israel's Channel 10 private television network said.
Earlier, a spokesman for the Free Gaza Movement which organised the six-ship flotilla said at least two were killed.
Casualties could hurt Israel's international image and diplomatic relations, especially with its long-time regional Muslim ally Turkey, whose flag some of the aid ships were flying.
Israel has said it was absolutely determined to maintain its blockade of the Hamas-controlled Gaza Strip, a Palestinian territory of 1.5 million. It has previously halted such activist ships, although others have reached Gaza before.
Amid Israeli military censorship and a refusal of Israeli officials to comment on what appeared to be a continuing operation three hours after dawn broke over the Mediterranean, Channel 10 made clear it was not citing foreign sources.
After initially reporting that at least 10 people were dead, it later said the death toll was between 14 and 16. It said commandos who had boarded the convoy were still conducting searches and encountering what it called violent resistance.
“Two people have been killed on board the Turkish boat and 30 or more were wounded,” said Mary Hughes Thompson, a spokesewoman for the Free Gaza Movement, which was behind the convoy.
“As far as we know IDF (Israeli military) commandos descended on the boat from helicopters and took it over.”
The convoy set off in international waters off Cyprus on Sunday in defiance of an Israeli-led blockade of the Gaza Strip and warnings that it would be intercepted.
The flotilla was organised by pro-Palestinian groups and a Turkish human rights organisation. Turkey had urged Israel to allow it safe passage and said the 10,000 tonnes of aid the convoy was carrying was humanitarian.
Key ally
Turkey, long Israel's best Muslim friend and a key ally in a hostile Middle East, was highly critical of Israel's attack on Gaza 18 months ago, in which 1,400 Palestinians were killed.
Relations between the two states are now distinctly chilly and bloodshed at sea will do nothing to improve them.
CNN showed pictures of a commando apparently sliding down a rope and clashing with a man wielding a stick. Other TV images showed what appeared to be rubber boarding launches.
France 24 television aired video of a woman in a Muslim headdress holding a stretcher with a large bloodstain on it. Below her lay a man, apparently wounded, in a blanket.
Israel had said it would prevent the convoy from reaching the Gaza Strip.
Israel and Egypt tightened a blockade on Gaza after Hamas took over the territory in 2007. Israel launched a devastating military offensive in Gaza in December 2008 with the aim of halting daily rocket fire towards its cities.
Most of the 1.5 million Palestinians living in Gaza rely on aid, blaming Israel for imposing restrictions on the amount and type of goods it allows into the territory.
The United Nations and Western powers have urged Israel to ease its restrictions to prevent a humanitarian crisis. They have been urging Israel to let in concrete and steel to allow for post-war reconstruction.
Israel denies there is a humanitarian crisis in Gaza, saying food, medicine and medical equipment are allowed in regularly.
It says the restrictions are necessary to prevent weapons and materials that could be used to make them from reaching Hamas.