Israel would need a massive ground assault with tanks to rescue hostages in Gaza that would be a 'bloody mess' and devastate civilian areas, retired 4-star general says

• Rescuing hostages from Hamas would require a "massive" ground attack, said Ret. Gen. Barry McCaffrey.
• Israel has to punch into the dense Gaza strip with tanks and troops, and conduct searches, he said.

Israel must launch a fierce ground assault in the Gaza strip with armor and infantry if it hopes to recover dozens of hostages held by Hamas, retired four-star US Army Gen. Barry McCaffrey said.

"It's an almost impossible task," McCaffrey said on Sunday on MSNBC's "American Voices with Alicia Menendez."

Israeli forces would have to seize control of the ground level in Gaza and conduct house-to-house searches, he said.

"Armor, infantry force, supported by fighter aircraft, dominate the scene and then try to find them in basements and tunnels," said McCaffrey, who served in the Gulf War and led the US Southern Command from 1994 to 1996.

Women, children, and seniors are believed to be among those captured from Israel in an unprecedented wave of surprise attacks by Hamas on Saturday.

Israeli TV channels reported that 600 people are believed to have been killed so far in the series of attacks and rocket barrages, per the BBC. Meanwhile, at least 400 Palestinians have been killed by retaliatory Israeli strikes, Reuters reported, citing the Palestinian Health Ministry.

While officials haven't said exactly how many people were forcibly brought into Gaza, Israel's ambassador to the UK estimated on Sunday that 100 people have been taken hostage.

Resolving the hostage situation is Israel's "absolute key dilemma," McCaffrey said in separate remarks on Sunday evening on MSNBC's "Weekends with Alex Witt."

A mass rescue effort would see Israeli forces punching into a 140-square-mile region filled with 2 million people, while meticulously searching house, basements, and cellars, McCaffrey said.

Both Palestinian and Israeli casualties would soar, he warned.

"This is going to be a bloody mess. Catastrophic for the civilian population of the Palestinians as well as the IDF fighting their way in," McCaffrey said.

Tweeting about the hostage situation on Sunday, McCaffrey assessed "there will be no good tactical solutions for the IDF."

He linked another MSNBC appearance from Saturday in his post, in which he separately warned of immense risk and violence in such a rescue effort.

"It looks like a long, bloody fight, in which the advantages of the Israelis will be partially neutralized by fighting in urban warfare," he said.

"I don't know how they're going to solve this without massive casualties in their own forces, never mind catastrophic damage in the Gaza strip," McCaffrey added.

Israel's Defense Ministry did not immediately respond to a request for comment sent outside regular business hours.