JERUSALEM -  Israel has deported all but one of a group of women activists who tried to break its decade-long blockade of the Gaza Strip by boat, the interior ministry said Friday.

A ministry spokeswoman said the last activist would leave the country later the same day. Thirteen women, including Nobel Peace Prize winner Mairead Maguire of Northern Ireland, were detained on Wednesday after their sailboat was stopped around 35 nautical miles off the coast of Gaza.

The boat was diverted to the Israeli port of Ashdod, about 30 kilometres (18 miles) north of the Palestinian territory, and the women detained before being deported.

"All the boat's passengers have left Israel except a woman who will fly to Oslo this afternoon," interior ministry spokeswoman Sabin Haddad told AFP.

Dubbed "Women's Boat to Gaza", the boat was part of the wider Freedom Flotilla Coalition consisting of pro-Palestinian activists who regularly defy Israel's blockade of Gaza.

An operation in 2010 turned to bloodshed when Israeli commandos killed 10 Turkish activists in a raid on a flotilla, leading to a six-year break in diplomatic ties between the two countries.

Israel's decision to build new settlements far inside the West Bank weakens prospects for peace with the Palestinians, the European Union's diplomatic service said on Friday, echoing US criticism that a two-state solution was at risk.

The International Criminal Court has no deadline for deciding whether to investigate alleged war crimes by Israel and the Palestinians, an ICC official said on Friday.

“There is no time limit,” the ICC’s Phakiso Mochochoko told AFP during a visit to Israel and the Palestinian territories.

“In due course when the time is right, when all the conditions have been met and when we have assessed everything, then the decision will be made,” he added.

The Palestinians formally asked the ICC last year to investigate the Jewish state, which is not a party to the treaty that governs the court, for alleged war crimes.

Palestinian foreign minister Riad al-Malki presented the court with a dossier alleging violations during the 2014 Gaza war and another on Israel’s occupation and settlement of the West Bank and east Jerusalem.

Some 2,251 Palestinians, including 551 children, were killed in fighting between Israel and Gaza’s Islamist rulers Hamas and other factions, according to UN figures.

Israel is alleged to have used indiscriminate force against the blockaded territory, while Hamas is accused of firing rockets at Israeli civilian population centres and using Palestinians as human shields.

In January 2015 the ICC, the world’s only permanent war crimes court, opened a preliminary examination into alleged abuses by both sides but has not moved to a formal investigation.

The Palestinians have expressed frustration at the slow pace of proceedings. “There is no lack of evidence and we believe that the office of the prosecutor should have been moving much faster,” Ammar Hijazi, a Palestinian foreign ministry official, said Thursday.

Mochochoko refused to be drawn on a possible timeline. “At the moment I am not in a position to say whether it is a question of months, whether it is a question of days, whether it is a question of weeks,” he said, speaking in English.

“There is a lot of information, there is a lot of reports and there is a lot of work that needs to be done in order to analyse that information and to assess it.”

Mochochoko, a member of the ICC prosecutor’s office, arrived Wednesday at the head of a four-strong delegation for a five-day mission to Israel and the Palestinian territories.

They were expected in the Israeli-occupied West Bank on Saturday and Sunday.

Despite encouragement to do so by some Palestinians, the ICC delegation is not visiting Gaza even to explain their work during this trip.

Israel controls all access to the West Bank and to the Gaza Strip - except its border with Egypt.

The Palestinian decision to take its complaints to the ICC in January 2015 was a key cause of friction with the Israeli government, which temporarily froze the Palestinian Authority’s tax revenues in retaliation.

Mochochoko denied that Israel had blocked a visit to Gaza.

“The office of the prosecutor is independent and it is impartial. Nobody dictates the terms of anything to the office of the prosecutor,” he said.

He said the locations visited had been “accepted by both parties as the parameters for this particular mission at this particular stage in time.”

He said the delegation’s visit was purely about explaining the work of the court and not seeking testimony.

“At this stage...we do not have any mandate to engage with witnesses, we don’t have any mandate to collect evidence,” he said. “We are not doing any fact finding mission,” he added. “What the future holds for us, that remains to be seen.”