Mexico City, Mar 29 (IANS): At least 20 people were killed in an armed attack on Sunday night during a clandestine cockfight show in the municipality of Zinapecuaro in Mexico's Michoacan, local authorities reported on Monday.

The state Attorney General's Office explained in a statement that the killings took place on Sunday night in the town of Las Tinajas, Xinhua news agency reported.

A forensic services unit sent to the scene found 19 people dead of gunshot wounds (16 men and three women), while a 32-year-old man died on route to the hospital.

In addition, several other injured people were transported to area hospitals.

The Attorney General's Office said that an investigation has been opened to clarify what had happened.

Michoacan state has been affected for at least a decade by violence from drug trafficking criminal groups.

About 70 per cent of homicides registered in Mexico in 2021 were linked to organised crime, with record numbers in Michoacan, according to Mexico's Public Security Secretariat.