Israel said Thursday it will begin seizing cryptocurrency accounts used by the Palestinian Hamas group to raise money for its armed wing.

Israeli Defense Minister Benny Gantz ordered security forces to seize the accounts after a joint operation “uncovered a web of electronic wallets” used by Hamas to raise funds using bitcoin and other cryptocurrencies, the ministry said.

It said Hamas has been waging an online campaign to raise donations for its military wing, efforts that accelerated after the 11-day Gaza war in May. Cryptocurrencies such as bitcoin are favored for illicit transactions because they are perceived as hard to trace.

“The intelligence, technological and legal tools that enable us to get our hands on terrorists’ money around the world constitute an operational breakthrough,” Gantz was quoted as saying.

Last year, the U.S. Justice Department said it had seized millions of dollars from cryptocurrency accounts that militant groups, including al-Qaida and the Islamic State group, relied on to finance their organizations and violent plots.

The department said it had confiscated about $2 million, in addition to more than 300 cryptocurrency accounts, four websites and four Facebook pages related to the schemes.

One prong of the U.S. investigation targeted the military wing of Hamas. Law enforcement officials seized more than 150 cryptocurrency accounts that they say laundered funds to and from accounts operated by the group.

Hamas, which seized Gaza from rival Palestinian forces in 2007 and has fought four wars with Israel, is considered a terrorist group by Israel and Western countries.