International activists delivering medical aid arrived in Gaza on Saturday in the latest attempt to break the Israeli-imposed blockade on the coastal territory.

Fifteen activists, including two from a Qatari charity, left the port of Larnaca late on Friday aboard a cabin cruiser.

Free Gaza Group spokeswoman Greta Berlin confirmed that the 66-foot yacht SS Dignity left Larnaca on Friday evening. It is scheduled to return to Cyprus on Monday.

She said the boat's 15 passengers are from Italy, Lebanon and Israel, and include two officials from the private Qatar Charity. They will tour Gaza looking for investment opportunities.

The boat is carrying a ton of medicine, baby food and 20 satellite tracking devices to be installed on Palestinian fishing boats.

The group has previously made four successful boat trips to Gaza. Three more trips are planned for next month.

Hamas, the Islamist group that controls Gaza, announced on the same day the end to a six-month Egyptian-brokered ceasefire with Israel.

Aid workers say the humanitarian crisis in Gaza, home to 1.5 million Palestinians, is escalating.

"After we assess the situation there, we will go back to Qatar and let the people know how we can help...and see how we can work to help relieve this terrible situation in Gaza," said Alze Al-Qahtani, who represented a charity from Qatar.

On Thursday the United Nations Relief and Works Agency, UNRWA, which provides food assistance to half the Gazan population, suspended distribution until further notice.

The agency said it had no stocks in its warehouses, blaming continuing cross-border violence and Israel's closure of crossings.