A court in southwestern China has executed three men convicted of masterminding a knife attack last year that killed 31 people outside a railway station in the city of Kunming.

A notice from the Kunming City Intermediate People's Court said Iskandar Ehet, Turgun Tohtunyaz and Hasayn Muhammad were put to death Tuesday.

The executions came after China's Supreme Court upheld their convictions for the crimes of murder and organizing and leading a terrorist organization.

Five knife-wielding assailants hacked 31 people to death and injured 141 on March 1, 2014. Four of the assailants were shot dead at the scene and one captured and sentenced to life in prison.

Beijing has blamed separatists and Muslim extremists for a spate of recent violence that has caused hundreds of deaths last year.