Justin Trudeau, Canada’s prime minister, has deplored the shooting of a Canadian doctor by an Israeli sniper on the Gaza border and added his voice to calls for an independent investigation into Israeli fire that killed 60 Palestinians and injured thousands more during mass border protests.

The violence erupted during demonstrations at the Gaza border fence on Monday, coinciding with a ceremony to mark the transfer of the US embassy from Tel Aviv to Jerusalem.

Most of the Gazans who died were shot by Israeli snipers, according to Gaza’s health ministry. They included eight children under the age of 16, it added. At least 2,700 people were wounded.

Trudeau described the reported use of excessive force and live ammunition as “inexcusable” in a statement.

“Canada deplores and is gravely concerned by the violence in the Gaza strip that has led to a tragic loss of life and injured countless people,” he said. “We are appalled that Dr Tarek Loubani, a Canadian citizen, is among the wounded – along with so many unarmed people, including civilians, members of the media, first responders, and children.”

Loubani, who works as an emergency physician in southern Ontario, said he was treating injured Palestinians on the Gaza Strip when he was shot in both legs on Monday. He was in Gaza as part of a medical team that is field testing 3D-printed medical tourniquets.

The shooting happened during a lull in the protests, said Loubani. He was wearing a green surgeon’s outfit and was standing with orange-vested paramedics about 25 metres from the protesters. There were no fires or smoke and he was within clear lines of sight to three fortified sniper posts.

“It’s very hard to believe I wasn’t specifically targeted, considering that there was a lull in activity, considering the fact that I was so clearly marked,” he told the Canadian Broadcasting Corporation earlier this week as he recovered from the shooting.

Another 16 paramedics were injured. The doctor who rescued Loubani, Musa Abuhassanin, was later killed as he was trying to reach another patient.

Trudeau said his government is working with Israeli officials in an attempt to determine how Loubani was injured. While Trudeau’s statement ranked as his government’s strongest criticism of Israel to date, it did not mention Israel by name.

The prime minister said Canada will work closely with international partners and institutions to address the situation. “It is imperative we establish the facts of what is happening in Gaza,” said Trudeau. “Canada calls for an immediate independent investigation to thoroughly examine the facts on the ground – including any incitement, violence, and the excessive use of force.”

The killings have prompted international condemnation with Theresa May, the British prime minister, and the United Nations secretary general, António Guterres, among those calling for an independent investigation.

Israel’s prime minister, Benjamin Netanyahu, joined the US in blaming Hamas for the deaths. Netanyahu defended his country’s use of force, saying: “Every country has the obligation to defend its borders.”