A Gaza boat designed to break Israel’s blockade en route to Europe was damaged in an explosion early Tuesday morning, with organizers alleging sabotage.

According to multiple sources, Gaza’s Ark, currently being rehabilitated for a symbolic journey to Europe, was rocked by a pre-dawn blast and is now partially sunk in Gaza port, the Palestinian News Network reported.

The boat was meant to symbolically break Israel’s naval blockade on the Gaza Strip, which has been in effect since 2007, when Hamas took control of the coastal enclave. Fishing boats are allowed to operate in a restricted area off the coast.

The project is sponsored by the Freedom Flotilla Coalition, the Palestinian Sailing Federation and the Fisherman’s Solidarity Campaign,

A member of the Gaza fishermen’s union told the Palestinian Al-Quds news outlet that the man guarding the boat received a call around 3:45 a.m. warning him to abandon the boat because it was going to be targeted in an attack.

The guard left, but returned after several minutes, just before an explosion went off.

While the guard was not injured, the boat was partially sunk in the harbor.

“Gaza’s Ark and all our partners in the Freedom Flotilla Coalition are considering our next move in response to this cowardly act of terrorism, but our position remains clear: Neither this nor any other attack will stop our efforts to challenge the blockade of Gaza until it ends,” David Heap of Gaza’s Ark Steering Committee said.

The boat was planned to sail later this spring and bring cargo from Europe to Gaza in a symbolic protest against the blockade.

“Freedom Flotilla boats have been sabotaged before. This attack comes as we were almost ready to sail. You can sink a boat but you can’t sink a movement,” Ehab Lotayef, another member of the Steering Committee added.

In 2011, two Europe ships slated to take part in a blockade-busting flotilla to Gaza were forced to cancel the trips after being damaged. Organizers in both cases claimed the ships had been tampered with.

Avi Issacharoff contributed to this report.