JERUSALEM (CNN) -- A truce in Gaza that was supposed to last three hours on Wednesday failed after just 15 minutes.

The suspension of the campaign from 1 p.m. until 4 p.m. was intended to allow residents of the Hamas-ruled Palestinian territory to receive food and medical supplies.

Israeli forces fired at militants in Gaza after Hamas militants targeted Israeli forces "almost immediately at 1 p.m.," according to Israeli Defense Ministry spokesman Peter Lerner.

While the guns fell silent for several hours on Wednesday, news reports from the Israel-Gaza border area said a string of explosions was soon heard after the three-hour lull ended. Israel said the three-hour lull would be repeated every other day between 1 p.m. and 4 p.m. to allow Gaza’s population to seek medical help, buy food and receive humanitarian supplies.