File photo: Members of the Lebanese security forces deploy during an anti-government protest in the capital Beirut. (AFP)
"A terrorist group had recruited young Palestinian men in Lebanon to carry out major bombing attacks using explosive belts" and other munitions, Interior Minister Bassam Mawlawi told a press conference.
"Three separate targets were to be hit at the same time," the ministry said, in an operation Mawlawi said would have caused a large loss of life.
Lebanon's Internal Security Forces (ISF) said the instructions for the bomb plot came from an IS operative based in the Palestinian refugee camp of Ain al-Hilweh, who is in touch with fellow Sunni extremists in Syria.
The instructions were passed to an undercover ISF agent who had successfully managed to infiltrate IS networks in Lebanon.
On February 7, the ISF agent was instructed to prepare attacks on a Shia religious compound in the Al-Laylaki neighbourhood, the Imam al-Kazem compound in Haret Hreik and the Al-Nasser mosque in Beirut's Ouzai suburb, the ISF said.
He was given three explosive vests and other weapons to conduct the attacks on February 16, the ISF added.
Beirut's southern suburbs, a stronghold of Shia militant group Hezbollah, saw a wave of bombings in 2013 and 2014 carried out by Al-Qaeda linked militants in retaliation for Hezbollah's intervention in the civil war in neighbouring Syria on the side of the Damascus government
According to the ISF, the planned attack by IS was meant to "pay homage" to the group's slain leader Ibrahim al-Hashimi al-Qurashi, killed in a US raid on his home in rebel-held northwestern Syria last month.