MEXICO CITY (AFP) - A Mexican court on Wednesday sentenced the owner of a school where 19 children and seven adults were crushed to death in a 2017 earthquake to 31 years in prison.

"We achieved justice for the victims!" Mexico City attorney general Ernestina Godoy Ramos wrote on Twitter.

Monica Garcia Villegas, head of the private Rebsamen elementary school in the Mexican capital, was convicted last month of culpable homicide.

The court also ordered her to pay a total of 11.5 million Mexican pesos (S$731,000) in damages to the victims' families, a judicial source told AFP on condition of anonymity.

"We, the lawyers and the victims we represent, are satisfied," Fernando Castillo, lawyer for the relatives of those killed, told reporters.

The school owner, who spent more than a year on the run, maintains her innocence and plans to appeal, her lawyer said.

Garcia Villegas was arrested after it was discovered that she had built a large apartment on top of the classrooms, the weight of which is thought to have contributed to the building's collapse.

The school was the focus of worldwide attention in the hours after the 7.1-magnitude earthquake as rescuers raced to rescue survivors.

Activists say that cost-cutting by construction companies, combined with corruption or incompetence by the authorities, contributed to the collapse of buildings in the quake, which left 369 people dead.