Three Palestinian fishermen have been killed in a blast off the coast of Gaza, local media and the head of Gaza’s fishermen syndicate said.

The official WAFA news agency quoted sources as saying the three men had died on Sunday as a result of a “mysterious explosion”.

Nizar Ayyash, head of Gaza’s fishermen union, told the QNN news website that the three men, all members of the same family, died after their boat was hit by a “missile” off Khan Younis.

Ayyash said the source of the projectile remains unknown.

The interior ministry said in a statement it was investigating the incident.

The Israeli military has denied responsibility for the incident.

“The [Israeli military] is not responsible for the incident, and our indications show that their deaths were caused by an explosion inside Gaza,” it said in a statement.

WAFA news agency reported that the Israeli navy had earlier on Sunday opened fire at Palestinian fishermen sailing off Gaza city, forcing the boat to return to shore.

Israel has maintained a blockade on the Gaza Strip since 2007. It imposes tight restrictions on the work of fishermen off the coast of the Gaza Sea, citing security reasons.

Gaza has approximately 3,000 fishermen, of whom only 800 work on some 700 boats. Some 70,000 Palestinians in Gaza make a living directly or indirectly from fishing, according to official Palestinian statistics.

Source: Al Jazeera