Prime Minister Benjamin Netanyahu said Monday that Israel would not pass up any opportunity to free more hostages from Gaza and described sustained military pressure until "total victory" over Hamas as necessary for their full recovery.

His statement was issued after Israeli special forces freed two hostages in a rescue operation in Rafah, a town on the Gaza Strip's border with Egypt packed with war refugees, where the prospect of wider operations has worried Cairo and Washington.

An Israeli government spokesperson added Monday that Hamas had been reduced to half its fighting force in the Gaza war, with more than 12,000 gunmen who have been killed and large numbers wounded or captured.

"We're talking about three-quarters of Hamas' battalions that have been shattered ... with over 12,000 terrorists who have been killed," Eylon Levy said in a briefing.

"When you take into account the number of terrorists who have been wounded or apprehended, that is more than half of Hamas' fighting force knocked out of action."