The school board in Uvalde has fired the school district's embattled police chief for his much-criticised handling of the shooting that killed 19 children and two teachers in the Texas city three months ago.

The Uvalde Consolidated Independent School District Board of Trustees voted unanimously to fire Pete Arredondo. He had been on unpaid administrative leave since shortly after the 24 May shooting.

Mr Arredondo did not attend the meeting. A written statement from his attorney, George Hyde, was emailed to board members just before the board met.

It cited death threats that Mr Arredondo received and the district's lack of efforts to provide any protection for him.

Mr Hyde also wrote that the district was in the wrong for dismissing Mr Arredondo, saying it did not carry out any investigation "establishing evidence supporting a decision to terminate" him.

The board held a special meeting to consider the police chief's position

Mr Arredondo has come under scathing criticism for his handling of the massacre at Robb Elementary School in Uvalde, a small town in Texas Hill Country, about 129km west of San Antonio.

Parents of children who were killed and wounded in the deadliest US school shooting in nearly a decade had demanded the school board dismiss Mr Arredondo.

He was forced to resign his seat on the Uvalde City Council on 2 July. Three weeks later, the board was scheduled to decide Mr Arredondo's fate as the school district police chief, but postponed the meeting due to "process requirements" at the request of his attorney.

According to the Texas Department of Public Safety (DPS), Mr Arredondo acted as "incident commander" in charge of law enforcement's response to the shooting.

DPS officials said 19 officers waited for an hour in a hallway outside adjoining classrooms where the gunman was holed up with his victims before a US Border Patrol-led tactical team finally made entry and killed the suspect.

Mr Arredondo, they said, chose not to send officers to confront the suspect sooner, believing the immediate threat to students had abated after an initial burst of gunfire in the classrooms.

Mr Arredondo, who oversaw a six-member police force before he was fired, has said he never considered himself the incident commander and that he did not order police to hold back on storming the suspect's position.