Defense Minister Moshe Ya'alon on Wednesday signed a declaration which designates the Islamic State (IS) and the Lebanon-based Abdullah Azzam Brigades terrorist groups as unlawful organizations.
The designation allows for legal action and other measures against these organizations, as well as against anyone fundraising for them or carrying other activities associated with these organizations.
The signing of the declaration was done in accordance with the recommendation of the Israel Security Agency (Shin Bet).
The declaration comes a day after the IS released a video which shows the beheading of American journalist Steven Sotloff who, it was later revealed, made aliyah to Israel in 2005 by himself, and studied at the Interdisciplinary Center (IDC) Herzliya.
The Abdullah Azzam Brigades has a long history of waging violent attacks against Hezbollah, the Iranian-backed Shia group which has drawn anger among Sunni Muslims for aiding the Syrian regime of Bashar al-Assad against the mainly Sunni rebels fighting to oust him.
The group's most high-profile attack came late last year, when it claimed responsibility for the November 19, 2013 bombing of the Iranian embassy in Beirut. The blast ripped through the embassy, located in a Hezbollah stronghold of the capital, killing 23 people and wounding 146.
The group has also previously claimed responsibility for rocket attacks from Lebanon towards northern Israel.