PCHR says that Israeli UAVs, or UCAVs - the C stands for combat - fired missiles into the Gaza Strip, killing three Hamas operatives, a Fatah fighter and three civilians last month. Other sources say that more than 40 people have been killed by UCAVs since 2004.
Israel has denied using UCAVs against the Gaza Strip, and says that air attacks have been carried out solely by the air force.
The final Israeli soldiers left Gaza on September 12 last year after 38 years of occupation. In the year since they left, killings of specific targets have risen.
B'Tselem, the Israeli information centre for human rights in the occupied territories, has stated that in the 12 months before Israel's withdrawal, 373 Palestinians were killed by Israeli security forces in the occupied territories.
In the 12 months afterwards, however, B'Tselem recorded that 503 Palestinians were killed by Israeli security forces.
Israel's withdrawal from Gaza has not reduced the death rate there.
The human rights organisation also recorded that so-called "targeted killings" of Palestinians rose by 16 during the year after withdrawal.
However, the number of Palestinians civilians killed as a result of the attacks also increased.
UAV surveillance has strengthened Israel's ability to monitor the movements of Palestinians and so attack them more easily, without using forces on the ground.
B'Tselem's figures suggest that despite heightened UAV surveillance, the accuracy with which the Israeli military has carried out attacks since September last year has decreased.
State-owned Israeli Aircraft Industries (IAI) is Israel's largest supplier of specialist aircraft equipment.
Mickey Bar, head of the company's military aircraft group, siad: "Some of the manned platforms existing today have no advantage over the unmanned."
"The UCAV is the future of aerial combat"
John Pike, globalsecurity.org
"By the end of the next decade, I believe that more than half of IAF platforms will be unmanned."
While Israel maintains that UCAVs have not carried out attacks in Palestinian territory, production at IAI suggests that it may soon change its line.
The aircraft technology manufacturer has developed Israel's first UCAV, called Eitan. Its specifications allow for "deep strikes and maritime patrol missions" and it has been flown this year.
John Pike, the director of globalsecurity.org and an expert on defence and intelligence policy, said "an armed UAV provides an immediate response to what might be a fleeting target of opportunity".
While UAVs are currently used for reconnaissance and tracking potential targets, "the UCAV is the future of aerial combat".
Israel is the largest user and producer of UAVs in the Middle East, but it is not the only state using them.
According to the Jaffee Centre for Strategic Studies (JCSS), the United Arab Emirates has many UAVs and mini-UAVs in operation and Iran has developed its own UAV industry, which began in 1997 when its UAVs shadowed US naval operations in the Gulf.
In April last year, Hezbollah flew an Iranian-made UAV over settlements in Galilee before returning it to southern Lebanon. Three UAV flights have been made by Hezbollah in two years.
Hassan Nasrallah, the secretary-general of Hezbollah, endorsed the use of UCAVs saying that they "can be laden with a quantity of explosives, [of] 40 to 50 kilograms," with reach "anywhere, deep, deep" into Israel.
Despite Israeli air force claims to have shot down a Hezbollah UAV in August during its war against the Lebanon, UAV interception looks likely to remain difficult.
Brigadier-General Ruth Yaron, the Israeli military chief spokeswoman, said: "It's like catching a mosquito with a net."
At present Israel has the capacity to launch UAVs equipped with air-to-ground and anti-missile weapons that may keep an enemy from using its weapons effectively.
However, one Israeli air force official said: "If you rely on one tool, like UAVs, that are very sensitive to technology, you can find yourself in an unpleasant situation.
"To control and maximise the various factors you have to be there. The smell and the colour of the theatre are necessary for you to analyse and understand any surprise situation."