Hamas says it thought Israel would manage to stop its attack sooner, and couldn't believe how successful it was

• Hamas was surprised by the success of its attack in Israel, a Hamas leader told the Associated Press.
• Ali Barakeh said the Israeli army suffered a "great collapse" and likened it to a "paper tiger."

Hamas was shocked by the success of its surprise attacks over the weekend, and how weak Israeli forces proved to be against their offensive, a senior figure of the militant group told the Associated Press.

"We were surprised by this great collapse," Ali Barakeh, a member of Hamas' exiled leadership, said, per the news agency.

Barakeh added that Hamas militants were "planning to make some gains and take prisoners to exchange," but found the Israeli army was like a "paper tiger," he said.

On Saturday, Hamas fighters launched a surprise sea, air, and ground offensive that seemingly caught Israeli intelligence off guard, according to military analysts.

David Khalfa, of the North Africa and Middle East Observatory at the Fondation Jean-Jaurès, told France 24 that the attack was a "historic failure" for the Israeli intelligence service.

Bruce Hoffman, a senior fellow for counterterrorism and homeland security at the Council on Foreign Relations, told NPR that: "No national intelligence agency is omniscient or flawless, but this is just a colossal failure."

Israel is considered to have one of the most advanced intelligence networks in the Middle East, with key agencies and informants embedded inside military groups, BBC security correspondent Frank Gardner said.

Israeli government sources told Gardner that a major investigation into how Israeli intelligence failed to predict the attack is now underway, with one official indicating that the probe could last years.

Barakeh also told the AP that Hamas had, to date, only employed a small proportion of its forces. He said nearly 2,000 Hamas fighters had taken part in the fighting, out of 40,000 in Gaza alone.

Those numbers could not be independently verified.

Shortly after Hamas launched its attack, Israeli Prime Minister Benjamin Netanyahu declared a "state of war," with the stated goal of eliminating the militant group.

On Monday, Israel announced a "complete siege" of Gaza, pledging to cut off its electricity, food, water, and fuel.