Palestinian security sources said on Saturday that the target was a metal workshop located at the entrance to the camp.
Palestinian witnesses said one person was injured in the attack, which occurred in a crowded residential area of the refugee camp.
Late on Friday, an Israeli helicopter gunship fired 10 missiles at two metal workshops in Gaza City's Zaitoun neighbourhood, completely destroying them and wounding four passers-by.
An Israeli army spokesman alleged the workshops, along with two others the Israeli occupation forces had struck on Friday in Gaza City, had been used by Hamas and other militant groups to produce rockets and other munitions to use against Israeli towns.
A family who owned the workshop struck on Saturday strongly denied it had been used to manufacture weapons and said it served as a mechanical workshop and as storage space for lumber.
Saturday's air raid came just hours after several makeshift Palestinian rockets and mortar rounds were fired at targets in southern Israel and at illegal Jewish settlements in Gaza Strip.
The rockets and mortar rounds caused no injuries or damage.
Palestinian ambulances rushed to the scene as hundreds of
neighbours filled the streets in panic and men shouted "Allahu
Akbar" (God is greatest) and "This is injustice."
Blocks and parts of debris from the zone flew in the air from the blasts.
Palestinians run for cover after
an Israel fired missiles into Gaza
Palestinian policemen screamed at residents in the area to leave. They said a third missile did not explode.
"We saw the helicopters," said Abu Ahmed, 45. "We expected
that someone [had been] assassinated and hoped it did not happen. Now it is clear it was a workshop. It was an act of sabotage.
"They terrorised the children."
Earlier on Saturday, an Aljazeera correspondent in Palestine reported that Israeli occupation forces, backed by Apache helicopters, stormed the Qalandia refugee camp south of the West Bank city of Ram Allah.
"At the same time clashes, erupted in the camp's lanes between the occupation forces and Palestinian teenagers.
"Eyewitnesses said a special unit cordoned off the camp's coffee shop which was full with people", the correspondent said.