A humanitarian organization backed by the United States and Israel did not distribute any food aid on Saturday, accusing Hamas of making threats that "made it impossible" to operate in the enclave, which the Palestinian militants denied.
The Gaza Humanitarian Foundation, which uses private U.S. security and logistics firms to operate, said it was adapting operations to overcome the unspecified threats. It later said in a Facebook post that two sites would reopen on Sunday.
Israel and the United States have accused Hamas of stealing aid from the U.N.-led operations.
The Israeli military said on Saturday that 350 trucks of humanitarian aid belonging to the U.N. and other international relief groups were transferred this week via the Kerem Shalom crossing into Gaza.
Israel makes the U.N. offload aid on the Palestinian side of the crossing, where it then has to be picked by the U.N. and aid groups in Gaza.
By Maayan Lubell, Jaidaa Taha and Nidal al-Mughrabi