The trio were part of a group charged in relation to a homemade bomb that went off in a hospital toilet in January 2020, and explosive devices found at a railway station the following month.

The two incidents caused no casualties.

The men were convicted last month of conspiracy to cause an explosion, which carried a maximum sentence of 20 years in prison. They were acquitted of more serious terrorism charges.

Lukas Ho, 41, received an 18-year sentence, with Judge Johnny Chan saying he had an "inflated ego" and showed no remorse, which posed a "risk to public safety".

His co-defendants, Lee Ka-pan and Cheung Ka-Chun, each received jail terms of 16 years and eight months.

The three men remained impassive during sentencing and smiled to friends and family in the public gallery as they were led away by guards.

The group was also linked to a third bomb plot which would have amounted to an "indiscriminate attack" had it not been foiled by police, prosecutors said earlier.

The court previously heard the plot was part of an attempt to force authorities to shut Hong Kong's borders in the early days of the pandemic, when the coronavirus was spreading in neighbouring mainland China.

A jury acquitted five other people in the same case last month.