Operation Agatha (sometimes called Black Sabbath) was a series of arrests made in Palestine on Saturday, June 29, 1946. About 2700 individuals were arrested in response to a number of attacks against British forces by the Unified Resistance units Haganah, Irgun and the Lehi.

The King David Hotel was the site of the British military command and the British Criminal Investigation Division. The Irgun chose it as a target after British troops invaded the Jewish Agency June 29, 1946, and confiscated large quantities of documents.The information about Jewish Agency operations, including intelligence activities in Arab countries, was taken to the King David Hotel.

The King David Hotel bombing is generally regarded as retaliation for Operation Agatha.