• Mohammed Deif leads the military wing of Hamas that carried out the recent attack on Israel.

• Deif is an elusive figure and is said to be the mastermind behind the Saturday attack.

• Only a few images of him are known to exist, including a shadowy silhouette believed to be Deif.

The mastermind behind Hamas's surprise attack on Israel on Saturday is so secretive that only a few images of the militant leader are known to exist, including a shadowy silhouette of the figure that is sometimes used in demonstrations.

Mohammed Deif is the top commander of Hamas's military wing in the Gaza Strip, known as Izzedine al-Qassam Brigades, according to the US State Department.

In 2015, the US government designated Deif as a global terrorist, holding him responsible for deploying suicide bombers and carrying out kidnappings of Israeli soldiers. During the Gaza War in 2014, Deif led Hamas's offensive strategy, the State Department said.

Despite his pivotal role in some of Hamas's most notorious attacks, Deif remains an elusive figure.

His exact locations are unknown and he does not make public appearances, according to The Associated Press. Even his real name has yet to be confirmed, The Washington Post reported.

Only a few images of Deif exist, according to Reuters, including one of him in his 20s, another of him in a mask, and a shadowy silhouette believed to belong to the military leader.

That silhouette had previously been used during a demonstration in August 2014, showing support for Hamas militants fighting the Israeli forces.

Israeli officials say the Hamas attacks have so far killed more than 1,200 Israelis, according to the UN's Office for the Coordination of Humanitarian Affairs. At least 1,100 Palestineans have died as well, according to Gaza's Ministry of Health.

On Saturday, the day of the attacks, a Hamas TV channel announced that Deif would issue a rare statement, signaling to Palestinians that something important was about to occur, Reuters reported.

The statement was pre-recorded on audio tape and broadcast.

In the recording, Deif said that the attacks were a response to Israel's actions against Palestinians, calling the Hamas operation the "Al-Aqsa Flood" or "Operation Al-Alqsa Storm."

The phrase references the Al-Aqsa Mosque in Jerusalem, considered to be Islam's third holiest site. The location has been a frequent point of contention between Israelis and Palestinians. In April, Israeli police stormed the mosque, leaving dozens of worshippers injured.

"Righteous fighters, this is your day to bury this criminal enemy. Its time has finished. Kill them wherever you find them," Deif said in the audio recording, according to The New York Times. "Remove this filth from your land and your sacred places. Fight and the angels fight with you."

One Hamas source told Reuters that Deif and Yahya Sinwar, another leader of Hamas in Gaza, made the call to prepare the attack on Israel. However, Deif was the "mastermind" of the operation, the source said.

Israel, in response, formally declared war on Hamas on Sunday and has since led a nonstop bombardment of the Gaza Strip for the past several days.

United Nations officials have made warnings that the conflict is leading to a humanitarian catastrophe in an area that has already been reliant on assistance from the United Nations Relief and Works Agency.

Israel's Defense Minister Yoav Gallant announced on Monday that food, fuel, and electricity supplies would be cut off from the region. The more than 2.3 million civilians in Gaza are unable to leave as the only viable exit through a route that leads into Egypt is blocked.

The IDF said Thursday that it was prepping more than 350,000 reservists for a possible ground war in Gaza, although a decision to invade the 140-square-mile strip has not yet been made.