Vessel carrying Palestinian patients, students and activists was captured by Israeli warships and taken to Ashdod port.

Israeli naval forces have intercepted a Palestinian vessel hours after it sailed off the coast of the besieged Gaza Strip.

The boat, carrying patients, students and people wounded in recent mass protests, was transferred on Tuesday to the Israeli port of Ashdod, according to the Israeli army.

The 17 people on board were attempting to break an Israeli-imposed siege for the first time in more than a decade, and had set off with the intention of reaching Limassol, a coastal city in southern Cyprus.

The intercepted boat had crossed nine nautical miles (16km) before four Israeli warships flanked the vessel.

Under the Oslo Accords signed in 1993, Israel is obligated to permit fishing up to 20 nautical miles, but this has never been implemented.

The widest range Israel has allowed boats in the past 10 years is 12 nautical miles (22km), and at times, the limit was reduced to one nautical mile (1.85km).

Boats are often limited to six nautical miles (11km), and Israeli forces regularly fire warning shots to boats attempting to breach it.

Although hundreds of people boarded more than 30 fishing boats in support of the main vessel, they did not cross the six-nautical-mile permitted boundary, Ramadan al-Hayek, one of the organisers of the voyage, told Al Jazeera

Fifteen boats attempted to cross more than nine nautical miles (16.7km) but met open fire by Israeli forces. These boats sailed in a show of support and were not aiming to reach Cyprus, al Hayek added.

Organisers of the voyage, called Break the Siege committee, also told Al Jazeera the captured boat went as far as 14 nautical miles (26km) when Israeli forces started shooting towards the vessel.

They lost contact with those on board shortly after that.

Passengers had valid passports, with the wounded having made arrangements to receive medical treatment in Turkey prior to leaving Gaza’s seaport.

According to al-Hayek, 17 people were detained by Israeli forces in Ashdod.

Committee members said they were working with international agencies, including Human Rights Watch and The International Committee of the Red Cross (ICRC), to ensure the wellbeing of the boat’s passengers and to hold Israel responsible for their safety.

Al-Hayek also said the committee would soon announce the launching of a second boat in response to Israel’s actions.

The Israeli military blamed Hamas, the party governing the Gaza Strip, for the naval “breach”.

In a series of posts on Twitter, it said the Palestinians will be returned to Gaza and warned the move would only “harm” residents of the strip.

It also said Israel would continue to enforce the blockade.

Moments ago, the Israeli Navy apprehended a Palestinian boat with approximately 17 Palestinians that attempted to breach the legal naval blockade. After a search of the boat and the Palestinians, the boat will be towed to the Israeli Navy base in Ashdod — Israel Defense Forces (@IDF) May 29, 2018

The IDF will continue to enforce the naval blockade and defend the maritime borders of Israel and its civilians — Israel Defense Forces (@IDF) May 29, 2018

Organisers reiterated that the voyage was a continuation of the Great March of Return, which began on March 30 with Palestinians rallying for the right of return for refugees to the homes and villages they were forcibly expelled from in 1948.

Since then, Israeli forces have killed at least 120 Palestinians in the coastal enclave and wounded at least 13,000 others.

Last week, the Palestinian government submitted a referral to the International Criminal Court (ICC) for the first time, calling on prosecutors to open an immediate investigation into what it called Israeli crimes in the occupied Palestinian territories.

The United Nations repeatedly warned that the effects of the blockade could make Gaza “uninhabitable” in the next few years.

In 2007, following the election victory of Hamas and the group’s assumption of control over the territory, Israel imposed a strict land, aerial and naval blockade on Gaza.

And in 2013, neighbouring Egypt, which has largely closed its border crossing with Gaza, blocked tunnels connecting Gaza with Egypt’s el-Arish, shutting off the only other route out of the strip.

With severe restrictions on access to basic services, Gaza – home to more than two million people – has been dubbed the world’s largest open-air prison.