A flotilla of Pro-Palestinian activist-led boats, which was scheduled to bring tonnes of lifesaving aid supplies to Gaza and set sail on Friday has had its departure delayed again due to "Israeli tactics", according to the group.
The Freedom Flotilla Coalition (FFC) made up of dozens of boats from around the world, was due to depart Istanbul on Friday having completed all technical and crew requirements, but late on Thursday it faced a sudden holdup.
"We received word of an administrative roadblock initiated by Israel in an attempt to prevent our departure," a statement from the FFC said on Thursday.
"Israel is pressuring the Republic of Guinea Bissau to withdraw its flag from our lead ship – Akdeniz. This triggered a request for an additional inspection, this one by the flag state, that delays our April 26 planned departure."
The convoy, including boats from over 40 countries and led by hundreds of volunteers from locations ranging from Hawaii to Malaysia, aims to break Israel's blockade on the Gaza Strip, where thousands face hunger and disease after nearly seven months of war.
Volunteers have been in Istanbul since April 18 and have been organising some 5,000 tons of humanitarian aid. It is the third time the boat's departure has been pushed back.
However, Israeli authorities have reportedly threatened to push the flotilla back from Gaza's coast, raising fears of an incident similar to the deadly 2010 Mavi Marmara incident, where Israeli commandos opened fire on Turkish activists, killing nine.
Some 800 people are volunteering on board the flotilla, including human rights observers, doctors, and US army veterans.
South African politician Nkosi Zwelivelile Mandela, the grandson of Nelson Mandela, is also onboard and said on Thursday that "we are looking forward to breaking the siege and breaking the blockade on Gaza".
The FFC described the additional inspection request as "another example of Israel obstructing the delivery of life-saving aid to the people in Gaza who face a deliberately created famine".
"How many more children will die of malnutrition and dehydration because of this delay and ongoing siege which must be broken?"
It added that all vessels have passed the required inspections at the port of Istanbul and that the team hopes that the departure will happen in the coming days, "provided there is no political interference".
The majority of Gaza's 2.3 million population has been displaced and is dependent on aid for survival. Around 30 Palestinian civilians, including children and the elderly, have died of starvation in recent weeks as Israel's restrictions on supplies have led to grave shortages of basic necessities such as food, water and medicine.
Aid workers have expressed concerns that the famine is likely to get worse and those in north Gaza are believed to be the most vulnerable. Months of Israeli siege has routinely blocked aid convoys from reaching the north, UN agencies have reported.
The United States announced on Thursday that its military had begun building a floating pier off the coast of Gaza, designed to facilitate aid delivery via sea channels.
The US has pressed Israel for months to improve mechanisms for aid delivery and distribution, which has been widely criticised by humanitarians as inefficient and dangerous.