Israel seizes second activist ship attempting to break Gaza siege

A Swedish-flagged ship heading for besieged Gaza has been seized by the Israeli navy, activists said on Saturday, with the crew detained for questioning.

It was the second time in a week that Israel has intercepted a ship from a four-vessel flotilla heading for the blockaded Palestinian enclave.

The 12 activists on-board the "Freedom for Gaza" boat were attempting to bring urgently needed medical supplies to Gaza, when the vessel was intercepted by the Israeli navy in international waters. 

The vessel was taken to the Israeli port of Ashdod, while the crew were detained for "further enquiry".

"The ship was monitored and was intercepted in accordance with international law," the Israeli military claimed.

"The (military) clarified to the ship's passengers that they are violating the legal naval blockade and that any humanitarian merchandise can be transferred to Gaza through the Port of Ashdod."

The vessel was the second of four ships from the "Freedom Flotilla" that have set sail from Scandinavia in an attempt to break the blockade on Gaza. 

"The demands of Ship to Gaza are that the ship with its crew and cargo will be returned to the site of the boarding, and that they will be allowed to go in peace through international and Palestinian waters in accordance to international law," they said in a statement.

"This is a demand that the eleven years-long illegal and destructive blockade on Gaza will be lifted at last."

The first boat was intercepted by Israel on Sunday with two other ships expected to attempt the journey to Gaza.

The Palestinian enclave has been under siege by Israel and Egypt for 11 years in an attempt to pile pressure on the Hamas administration that runs Gaza.

The UN and human rights groups have appealed to Israel to end the siege on Gaza, which has had a devastating impact on the 2 million Palestinians living in the territory.

Essential goods, such as building materials and medicine, are running in extremely short supply due to the blockade.