At least 12,000 people have been killed in Iran in the largest killing in the country`s contemporary history, much of it carried out on January 8 and 9 during an ongoing internet shutdown, according to senior government and security sources speaking to Iran International, writes iranintl.com.

After cross-checking information obtained from reliable sources, including the Supreme National Security Council and the presidential office, the initial estimate by the Islamic Republic`s security institutions is that at least 12,000 people were killed in this nationwide killing.

Iran International reached the conclusion after reviewing information it received from a source close to the Supreme National Security Council; two sources in the presidential office; accounts from several sources within the Islamic Revolutionary Guard Corps in the cities of Mashhad, Kermanshah, and Isfahan; testimonies from eyewitnesses and families of those killed; field reports; data linked to medical centers; and information provided by doctors and nurses.

The killing was carried out on the direct order of Supreme Leader Ali Khamenei, with the explicit knowledge and approval of the heads of all three branches of government, and with an order for live fire issued by the Supreme National Security Council, Iran International has learned.

Iran International`s Editorial Board has set out its findings on the latest crackdown in a statement titled "The killing of 12,000 Iranians will not be buried in silence", calling for documents and testimony by the victims` families.