The school board in Uvalde, Texas, is urging Gov. Greg Abbott (R) to hold a special legislative session to raise the minimum age at which assault rifles can be purchased to 21, two months after a gunman who attacked an elementary classroom legally bought two semiautomatic rifles within days of turning 18.

The board voted unanimously Monday night to pass the resolution calling for Abbott to hold the special session, which would see lawmakers recalled to the state capital, Austin. Texas is among more than a dozen states where only the governor can call special sessions.

The age requirement should be raised from 18 to at least 21, Uvalde Schools Superintendent Hal Harrell said at the board meeting Monday. The gunman who entered a fourth-grade classroom at Robb Elementary School in May took "the lives of 19 students and two teachers with a rifle that an 18-year-old could walk in and purchase," he said.

"There's no reason for an 18-year-old to have something like that," Harrell said, to applause.

The school board members are among a growing group of leaders at the local, state and federal levels calling for 21 to be the minimum age for purchasing powerful weapons. President Joe Biden, in the wake of the Uvalde shooting, said raising the age at which assault weapons can legally be bought was the least Congress could do, if banning such weapons was politically impossible.

Uvalde County commissioners have also asked Abbott to call the special session, according to the Austin American-Statesman. The new restrictions would resemble those passed by Florida, which in 2018 raised the age limit for purchasing long guns to 21 after the deadly shooting at Marjory Stoneman Douglas High School.

Abbott's office did not immediately respond to a request for comment about the school board's vote. A spokesperson for the governor told the Texas Tribune that "all options remain on the table."

"More announcements are expected in the coming days and weeks as the legislature deliberates proposed solutions," the spokesperson said.

The board also voted Monday to postpone the start of Uvalde's upcoming school year from Aug. 15 to Sept. 6 as officials work to tighten campus security in the wake of the May assault. A report released last week found some security protocols weren't being followed, along with failures from every law enforcement agency that responded to the attack.

The nearly 400 local, state and federal officers at the scene that day have been criticized for their inaction. The report said it wasn't clear whether swifter action could have saved lives, but didn't rule out the possibility.