Israel has consistently denied aid convoys to northern Gaza, according to the UN’s agency for Palestine refugees (UNRWA).

Food shortages are worst in northern Gaza, where Israel concentrated its military offensive in the early days of the war.

Israeli authorities vetoed at least 27 out of 81 aid missions that require coordination in the north and south of the strip, between April 1 and April 19, UNRWA said in a report. The last time UNRWA was able to deliver food supplies to the area was on January 23.

The Israeli agency in charge of inspecting convoys entering Gaza told CNN earlier this month that it was “cooperating [in the north] with a wide array of humanitarian organisations” including UN agencies and regional actors.

Since the beginning of April, an average of 186 aid trucks have crossed into Gaza per day via the Kerem Shalom and Rafah land crossings, UNRWA said.

As of April 8, UNRWA said it had delivered flour to nearly 400,000 families in southern Gaza. Before the war, about 500 trucks of supplies were entering the Palestinian enclave daily.

Barely trickling in: Human rights agencies have repeatedly warned that Israel’s severe restrictions on aid entering Gaza means relief is barely trickling into the strip.

UNRWA says there “has been very little significant change in the volume of humanitarian supplies entering Gaza or improved access to the north.”

Israeli agencies have frequently blamed the UN for failing to distribute aid within Gaza, saying last week that hundreds of trucks of aid piled up at Kerem Shalom.

Cargo trucks carrying humanitarian aid move through the security inspections before crossing into the Gaza Strip, in Kerem Shalom, Israel, on March 14. Marcus Yam/Los Angeles Times/Getty Images