Twenty-two places in Hong Kong were raided in an operation linked to the detonation of an explosive device earlier this year. A small bomb was detonated on January 27 inside a public toilet at a hospital in Hong Kong's working-class district of Sham Shui Po, and attempts were made in the following week to set off two other devices at border checkpoints. Two Hong Kong groups claimed responsibility at the time, saying a shutdown of border crossings was needed to curb the spread of the deadly new coronavirus to the city.