Houston, Nov 18 (IANS): Lt. Mariano Pargas, who was the acting police chief during the May 24 mass school shooting in Uvalde, Texas, has resigned from the city's police department, a top official announced.

His resignation is effective immediately, Uvalde Mayor Don McLaughlin said on Thursday.

Pargas, who had been suspended with pay since July, was expected to be terminated at a "special meeting" scheduled for Saturday, reports Xinhua news agency.

An audio recently published by CNN showed that on the day of the shooting at Robb Elementary School, the 65-year-old Pargas knew there were children alive and begging for rescue but walked away from the locked classroom without taking action.

He, along with the city of Uvalde and the school district, currently faces a lawsuit from the families of three survivors.

The Uvalde Consolidated Independent School District (CISD) suspended the entire school police force last month partly as a result of parents' protest over the fallout from police response to the school shooting.

A total of 376 law enforcement agents, including the school police officers, responded to the shooting but failed to intervene for 74 minutes, according to a Texas House committee report.

On May 24, the 18-year-old gunman Salvador Ramos stormed in to the Robb Elementary School and killed 19 children and two teachers.

The school has been closed since then.

Children who would have gone to Robb now instead go to another two elementary schools in the city.

A virtual academy is also available for the families who don't want to send their students back to school.

This was the third-deadliest school shooting in the US, after the Virginia Tech shooting in 2007 and the Sandy Hook Elementary School shooting in 2012, and the deadliest in Texas.