Shanaa was travelling to al-Bureij camp to cover the aftermath of the air raid there.
Jacky Rowland, Al Jazeera's correspondent in Jerusalem, said the car in which Shanaa was travelling was "clearly marked with 'press' symbols".
"It was even clearly marked on the roof, so it can't be mistaken on the ground or from the air," she said.
"It is quite inconceivable that Israeli forces, who are looking over the territory with drones, helicopters and aeroplanes, were unfamiliar with this car."
An Israeli military spokesman said: "We regret the death of a photographer, but it must be pointed out that there's a war going on against armed terrorists who are extremists and dangerous."
"Members of the media or civilians put themselves in danger by entering a combat zone."
Five Palestinians, all of them from the armed wing of the Palestinian Hamas movement, were killed in clashes with Israeli troops earlier in the day.
The Israeli army said it lost three soldiers and that three more were wounded in an exchange of fire near the security fence between Israel and the Palestinian territory.
Hamas said that it killed the soldiers in a "sophisticated ambush" in Gaza City. The deaths were not immediately confirmed by the Israeli military.
An Israeli army spokeswoman said that troops entered the territory to target Palestinian fighters launching rockets.
She said that troops exchanged fire with Hamas fighters at several points, hitting some.
In one battle, Israeli troops were "targeted by Palestinians and there were several casualties," she said, adding that there had been several incidents and that Palestinians had used anti-tank missiles and mortars as well as assault rifles.
Hamas officials said that the Israeli soldiers were supported by helicopter gunships during the fighting near the Nahal Oz border terminal.
|Hamas said that it carried out a "sophisticated |
ambush" on Israeli forces in Gaza City [AFP]
Two Israeli civilians, two Palestinian civilians and two fighters were killed in an attack on the border crossing last week, the only terminal for supplying fuel to the Gaza Strip and its 1.5 million people.
Fuel deliveries, which were halted after the April 9 attack, were resumed on Wednesday, Israeli and Palestinian officials said.
Israeli officials had said earlier on Wednesday that the terminal would not be reopened.
The move to resume fuel deliveries came a day after the UN called for Israel to re-open supplies to Gazan civilians.
Mahmoud Khuzandar, the deputy director of the Gaza fuel station owners' association, said Israel had pumped 90 tons of liquid gas for cooking and 180 thousand litres of fuel for the power station into Gaza.
However, an Israeli defence official said that they had only sent fuel for a power plant.