Image caption Activists have said they would not resist Israeli forces

Israel says its troops will board an Irish-owned aid ship attempting to break the blockade of Gaza if it does not change course.

The MV Rachel Corrie has defied instructions to dock at the Israeli port of Ashdod, Israel says.

"If they don't comply, we will have to board the ship," Lt-Col Avital Liebovich told the BBC.

It comes days after Israeli commandos stormed a Gaza-bound aid flotilla. Clashes on board left nine people dead.

That raid brought strong condemnation of Israel, especially from Turkey, from where most of the victims came.

The Rachel Corrie was 28 nautical miles (52km) off the Israeli coast, the Israel Defence Forces said at 0745 GMT.

MV RACHEL CORRIE Irish-owned, 1,200-tonne cargo ship

On board: Five Irish and six Malaysian activists, plus crew

Carrying aid, including wheelchairs, paper, medical supplies and cement

Israel says it has radioed the aid ship several times but received no response.

"We have contacted the boat, and we've asked them politely to change course to Ashdod port. If they will choose to do so, we promise them we won't board the ship," said Lt-Col Liebovich.

"If they don't do it willingly - if they don't comply - we will have to board the ship," she said.

The activists had earlier said they would not resist any Israeli attempts to stop the ship.

The Rachel Corrie is named after a US college student who was crushed to death by an Israeli army bulldozer as she protested over house demolitions in Gaza in 2003.

Condemnation

Israel has said if the ship docks at Ashdod, the aid will be delivered to Gaza by road after the cargo has been inspected for banned items.

Israel has blockaded Gaza since 2007, when the Islamist Hamas movement seized control of the territory.

There are five Irish and six Malaysian activists, plus several crew, on board the Rachel Corrie.

It had been a part of the previous flotilla, but was delayed by technical problems.

The Rachel Corrie is carrying hundreds of tonnes of aid, including wheelchairs, medical supplies and cement. Construction materials are banned from entering Gaza by Israel, which says they could be used for military purposes by Hamas.

The sea-borne mission has been organised by the Cyprus-based Free Gaza Movement, a coalition of pro-Palestinian groups and human rights organisations.

Israel has faced a storm of international criticism after its troops shot dead nine people during a violent confrontation on the Turkish Mavi Marmara in the early hours of Monday.

Accounts as to what happened when Israeli soldiers rappelled from helicopters on to the ship differ.

Israel says its commandos were attacked with weapons, including knives, and opened fire in self-defence. Pro-Palestinian activists on board say troops shot at them without provocation.