DALLAS -- Police were on alert Saturday evening after what was described as a credible threat was made against Dallas Police headquarters, CBS Dallas-Fort Worth reported.
SWAT officers were called to the scene and were checking the area, according to the station.
Sources told the station the police department received an anonymous message about a group coming from Houston with the intent to kill officers. One person from the group was spotted in Dallas, the sources said.
Police spokeswoman Sr. Cpl. Monica Cordova called the measures precautionary. On Twitter, Dallas Police said reports of shots fired were inaccurate and that police were searching a police parking garage for a suspicious person.
An armored vehicle was moved to near the department's downtown headquarters late Saturday afternoon and heavily armed officers were seen walking nearby. But members of the public were still able to walk about freely around the building.
The police department later tweeted that the parking garage was searched by officers and by police dogs, with no suspects being found. An all-clear was announced just before 8 p.m. Central time.
Other departments around the country have been receiving threats. They follow videos involving police shootings of black men in Louisiana and Mississippi and the killing of five police officers by a sniper in Dallas earlier this week.