Since the Egyptian-brokered ceasefire agreement between Israel and Hamas-ruled Gaza that ended eight days of war in November 2012, both sides have been engaged in what is known as the "battle of minds".
In the past two years, the Hamas-run Ministry of the Interior has announced at least two amnesty campaigns and rehabilitation programmes for collaborators working in Gaza and spying for Israel.
Since taking control of Gaza in 2007, one of the priorities of the government, especially with regards internal security, has been to work hard to combat the phenomenon of collaboration.
A ministry spokesperson in Gaza said the phenomenon of collaboration is miniscule and has declined as many have been arrested and others have turned themselves in.
He added that these collaborators, however, pose a real danger to the unity of the Palestinian people and their resistance against Israel, which has sealed off the narrow coastal enclave by land, sea and air.
The internal security of the Ministry of the Interior has held many lectures, workshops and awareness campaigns at different institutions including schools and mosques as well as local channels and radio stations to educate people about the different techniques used by the Israeli intelligence services to recruit informants.
Since Israel's unilateral withdrawal from Gaza in September 2005 and the redeployment of its forces around Gaza, it has become difficult for Israel to recruit informants. Israeli intelligence services now recruit new spies through a blackmailing procedure practiced against patients and fishermen at sea. They do this through blackmailing patients and their relatives as they leave Gaza, via the Israeli controlled Eriz crossing, in order to receive advanced medical attention at hospitals in the West Bank or Israel.
Many cases have been documented by human rights groups in Gaza showing patients were sent back after they refused to provide information about the activities of Palestinian resistance factions.
Many Gaza fishermen have been arrested by the Israeli navy which patrols the Gaza seashores around the clock, some fishermen said that they were asked to provide information and become spies in exchange of privileges, such as money or freedom of movement at sea.
According to internal security sources, social media, especially Facebook, is being used by Israeli intelligence service to gather information and recruit new collaborators. By pretending to be pro-Palestinians, Israel targets males and females and then builds a relationship with them and asks for information about the activities of resistance groups.
According to the ministry, some of the suspected collaborators were accused of aiding Israel in the 2008 war in which 1,417 Palestinians, including 281 children were killed, as well as in the 2012 war when 186 people were killed, including 47 children, and hundreds were injured.
"The enemy is constantly trying to recruit new collaborators in order to penetrate our internal front. But our security officers are working around the clock to counter the Zionist espionage measures. We are conducting awareness campaigns to protect our security and internal front," Islam Shahwan, spokesperson of the Gaza Ministry of the Interior, said.
The ministry said collaborators are treated according to Palestinian law. They are referred to military courts, have access to lawyers and have the right to appeal. Sometimes death sentences are reconsidered and replaced with jail terms.
Some experts say that recruiting new Palestinian collaborators does not mean Israel suffers from the lack of information, as reconnaissance drones and high-tech equipment are used to gather information, in addition to spies who are covert and still active. But Israel always seeks to gather and update information.
Samir Zaqqout from Al-Mezan Centre for Human Rights said: "It's true that there were achievements by the government in Gaza to fight this phenomenon, but since the communication between the spies and the Israeli intelligence are conducted individually, there are still many unknown, covert collaborators."
"I think the phenomenon of collaborators is an old one that existed a long time ago in the occupied Palestinian territories, including Gaza, and it is a very dangerous phenomenon. The government in Gaza says collaboration has declined shapely due to its campaigns to crackdown on collaborators, but I doubt it has decreased. I think the techniques and high technology used by the Israeli intelligence to communicate with the collaborators make it very difficult to uncover these spies."
Despite Israel's claims that it no longer occupies Gaza, it still maintains its full control over Gaza's air space, territorial waters and border crossings, except the Rafah crossing which is controlled by Egypt.
Israel exploited and still exploits its control over Gaza's border crossings to recruit more collaborators by blackmailing travellers or by contacting Gaza residents who are in need of aid and providing them money in exchange for information.
During the eight-day war in November 2012, six Palestinians who were suspected of spying for Israel were kidnapped from their prison and killed by masked gunmen who then chained the body of one of the alleged collaborators to a motorcycle and dragged it through the main streets of Gaza City.
Following the incident, Mousa Abu Marzouk, Hamas' deputy leader, condemned what he described as an "unlawful killing", adding that punishing collaborators, especially those involved in the killing of leaders of Palestinian resistance groups, must only be carried out in accordance with the law and through the legal procedures.
Shahwan said his ministry was clear when they told international and local human rights organisations that they are against the inhumane way in which these people were killed. He described the actions as uncivilised and a grave violation of the law, adding that his ministry conducted an official investigation and found the perpetrators and applied punitive measures against them.
As the anti-espionage campaign aims to cleanse Israel's alleged spies by giving them the chance to turn themselves in or face arrest and a possible death, the hidden war between Israel and Hamas is continuing despite the tranquillity on the ground.
The views expressed in this article belong to the author and do not necessarily reflect the editorial policy of Middle East Monitor.