A second convoy of 14 aid trucks entered the Rafah crossing from the Egyptian side to the besieged Gaza Strip last night, Juliette Touma, director of communications at the UN Relief and Works Agency (UNRWA), told Reuters in Gaza by phone from Amman.

Witnesses reported a blast and ambulance sirens on the border earlier. Israel’s military said one of its tanks accidentally hit an Egyptian position near the border with the Gaza Strip. Several Egyptian border guards sustained minor injuries after being hit by fragments of an Israeli tank shell, a spokesperson for the Egyptian army said.

A witness and a medical source said seven people were wounded and taken to hospital. Israel’s defence force “expresses sorrow regarding the incident, which is being investigated,” it said in a statement, giving no further details.

Egyptian security and humanitarian sources said as many as 19 trucks had entered from the Egyptian side of the crossing in Sunday’s convoy, carrying medical and food supplies. It was unclear if any aid was held back at the border.

UN officials say at least 100 trucks a day would be required in Gaza to cover urgent needs. Before the outbreak of the most recent conflict, several hundred trucks had been arriving in the enclave daily.