Medical staff carry an injured girl during clashes on Gaza-Israel border, east of the southern Gaza Strip City of Khan Younis, on Aug. 17, 2018. (Xinhua File photo)

GAZA, March 29 (Xinhua) -- The UN Relief and Works Agency for Palestinian Refugees (UNRWA) on Friday expressed deep concern over the "excessive use of force" by Israeli forces during the past year of the Great March of Return rally on the border between the eastern Gaza Strip and Israel.

The Israeli act is "contrary to applicable standards under international law," the UNRWA said in an emailed press statement.

Many of the injured are "in need of long term medical and psycho-social assistance," the statement added.

In addition, 13 of the UNRWA schoolchildren were killed and 227 others wounded in the past year, mostly aged 13 to 15.

"The 227 UNRWA schoolchildren might not be able to resume their education due to their injuries," the statement noted.

Earlier in the day, the Palestinian Ministry of Health in Gaza said 266 Palestinian demonstrators were killed during the past year of the Great March of Return rally along the Gaza borders close to Israel.