Valley police departments are in Uvalde supporting law enforcement agencies after the deadly tragedy that left 21 people dead on Tuesday. 

Other Texas cities have also sent law enforcement officers to assist law enforcement officers in Uvalde with the elevated service demand there, according to a news release.

"They are asking for assistance throughout the state for help with the calls for service in their community," McAllen Police Chief Victor Rodriguez said. "This circumstance is so big is so huge that our contribution to assist it pales in contrast to the magnitude of the incident."

Officers from the Hidalgo County Sheriff's Office, McAllen and San Juan Police departments traveled to Uvalde Friday morning. Edinburg Police department officers are expected to arrive on Saturday.

"In law enforcement, when a call goes out - we all respond," Hidalgo County Sheriff Eddie Guerra said. "In this case, a call has gone out and we're responding. This is what we do, this is a brotherhood in law enforcement."

McAllen Police department and the Hidalgo County Sheriff's Office each sent four officers.

McAllen Police department is sending another eight-person team Saturday and officers are returning to McAllen next Tuesday, according to Rodriguez. 

Hidalgo County Sheriff's Office law enforcement agencies will remain in Uvalde for the next week, according to Guerra.