GENEVA, April 27 (Xinhua) -- The Office of the UN High Commissioner for Human Rights (OHCHR) on Friday showed its severe concern over the many deaths and injuries sustained by Palestinians, including children, in Gaza in the past month.

According to OHCHR, during the past four weeks, 42 Palestinians have been killed and over 5,500 injured by Israeli Security Forces (ISF), among which 35 of those killed were taking part in demonstrations as part of the 'Great March of Return'.

Most of them appear to have been unarmed or not presenting an imminent threat to the ISF at the time of their killing or injury, OHCHR said.

"UN High Commissioner for Human Rights Zeid Ra'ad Al Hussein on Friday called on Israel to ensure that its security forces do not resort to the use of excessive force, he also called for those responsible to be held accountable," Rupert Colville, spokesperson for OHCHR, told a press briefing Friday.

The UN rights body emphasized that under international law, Palestinians have the right to peaceful assembly and expression, and the Israeli security forces, in policing the Gaza fence, must use only necessary and proportionate means to discharge their duties.

Saying that the impact on children is of great concern, OHCHR said that since March 30 of 2018, four children have been shot dead by Israeli forces, three of them by a bullet to the head or neck.

According to the UN rights body, a further 233 children have been injured by live ammunition, with some sustaining injuries that will result in lifelong disabilities, including through the amputation of limbs.