By Ian Lee, Abeer Salman and James Masters, CNN

(CNN) -- At least 43 Palestinians were killed by Israeli forces during clashes at the Gaza border Monday in the deadliest day there since the 2014 war, the Palestinian Ministry of Health announced.

The demonstrations were called to mark the official unveiling Monday of the new US Embassy in Jerusalem, which has been relocated from Tel Aviv in a controversial move that has been praised by Israelis but has enraged Palestinians.

Most of the dead were killed by Israeli fire near the border. CNN journalists there heard gunfire in spurts and saw a tank moving towards the fence in the border area of Malaka. Israeli drones also dropped tear gas over a crowd of protesters.

The Palestinian Health Ministry said more than 1,600 had suffered injuries, and that many of the dead had not yet been identified.

The Israel Defense Forces (IDF) released a statement Monday accusing the Palestinian militant group Hamas, which controls Gaza, of "leading a terrorist operation" and inciting protesters who had amassed by the border fence with Israel to conduct what Israel described as terror attacks.

The IDF estimated that around 35,000 people -- who it describes as "violent rioters" -- had assembled in 12 different locations along the border fence between Gaza and Israel and thousands more were gathered in a tent city about a kilometer from the border.

The military said the protesters threw Molotov cocktails, burned tires, and stones at Israeli soldiers positioned along the fence. The IDF also says it foiled an attack by three armed Palestinians near Rafah, close to the border with Egypt, during "a particularly violent demonstration."

The Palestinian Health Ministry said 443 injuries were caused by live ammunition, 320 by tear gas, and three by rubber-coated bullets.

The first victim to be named was Anas Hamdan Qdeih, a 21-year-old, who was shot dead by Israeli forces east of Khan Younis, according to the Palestinian Health Ministry.

Earlier, the Israeli army air-dropped leaflets over Gaza warning people not to approach the fence that separates Gaza from Israel.

More than 90 people have been killed by Israeli soldiers since the latest wave of protests began in March, according to a CNN count based on the Palestinian Ministry of Health figures.

Demonstrators say they want to highlight their right to return to homes lost by their ancestors during the war that accompanied the founding of the state of Israel in 1948.

Israel says the demonstrations are orchestrated by Hamas and has insisted its forces are acting "according to standard operating procedures."