Food supplies to Gaza have fallen sharply in recent weeks because Israeli authorities have introduced a new customs rule on some humanitarian aid and are separately scaling down deliveries organized by businesses, people involved in getting goods to the war-torn territory have said.

The new customs rule applies to truck convoys chartered by the United Nations to take aid from Jordan to Gaza via Israel, seven people familiar with the matter said.

Under the rule, individuals from relief organizations sending aid must complete a form providing passport details, and accept liability for any false information on a shipment, the people said. They said relief agencies are disputing that requirement, which was announced mid-August, because they fear signing the form could expose staff to legal problems if aid fell into the hands of Hamas or other enemies of Israel.