Outrage is mounting after Israeli leaders rejected international calls for an inquiry over its use of live rounds during a demonstration at the Gaza-Israel border which left at least 15 Palestinians dead.

More than a dozen funerals took place over the weekend following the deaths on “Land Day”, a symbolic day for Palestinians which kick starts a month and a half of sit-ins and protest.

Footage has emerged which appears to show men, from a group which left the main demonstration on Friday and approached the border, being shot in the back as they fled.

Nine protesters were killed by Israeli army bullets, a farmer was also killed by a stray tank shell hitting his field.

The use of live ammunition, alongside rubber bullets, has sparked calls for an inquiry from UN Secretary General Antonio Guterres, and EU foreign policy chief Federica Mogherini, among others who say the response was disproportionate.

This has been ruled out by Israel’s defence minister Avigdor Lieberman, who told Army Radio the soldiers “acted as necessary” and that some of the group had fired at soldiers and hurled rocks and flaming tyres.

“I think all our soldiers deserve a medal,” Mr Lieberman added. “As for a commission of inquiry – there won’t be one.”

He maintained that peaceful protesters were unharmed and troops opened fire on the instigators of a charge at the border.

Hamas, Gaza’s dominant Islamist movement which is designated a terrorist organisation by Israel, said five of those killed were its members, though Israel says eight of the men were part of Hamas.

Israel had bolstered its security at the border with paramilitary troops and snipers ahead of an annual commemoration of the land seizures and displacement of Palestinians.

A tent camp has been set up along the border for the duration of the “right of return” demonstrations which will culminate on 15 May, the 70th anniversary of Israel’s creation, with the intention to march through the border fence.

Many of Gaza’s two million inhabitants are descendants of the hundreds of thousands who fled that day, and Israel has ruled out any right of return.

Protesters were advised to stay 700 metres back from the border, and soldiers fired on those who came closer, including the tank shells on the morning of the protest.

The Palestinian health ministry says “1,000 were injured” by rubber bullets, live ammunition and tear gas.

“The use of live ammunition should, in particular, be part of an independent and transparent investigation,” Mogherini said in a statement on Saturday. “While Israel has the right to protect its borders, the use of force must be proportionate at all times.”

Additional reporting by Reuters