Hamas has recruited between 10,000 and 15,000 members since the start of Israel’s war on Gaza, according to two congressional sources briefed on US intelligence, suggesting the fighters could remain a persistent threat to Israel, Reuters reports.

The intelligence indicates a similar number of Hamas fighters have been killed during that period, the sources said. The latest official US estimates have not been previously reported.

The sources briefed on the intelligence, which was included in a series of updates from U.S. intelligence agencies in the final weeks of the Biden administration, said that while Hamas has successfully recruited new members, many are young and untrained and are being used for simple security purposes.

The US Office of the Director of National Intelligence declined to comment.

“Each time Israel completes its military operations and pulls back, Hamas militants regroup and re-emerge because there’s nothing else to fill the void,” then-President Joe Biden’s Secretary of State Antony Blinken had said previously.

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