Dallas police completed a search near its headquarters after receiving an anonymous threat on Saturday.
"The Dallas Police Department received an anonymous threat against law enforcement across the city and has taken precautionary measures" to heighten security, Dallas police said in an emailed statement to Reuters.
Police conducted a search at a department parking garage, but found no suspects, the department tweeted.
Earlier, Dallas Police said that officers were searching the police parking garage for a "suspicious person."
The Dallas Morning News also noted that a possible sighting of a masked man prompted police to go on heightened alert.
Dallas police Sgt. Warren Mitchell told Dallas Morning News reporter Naomi Martin that no shots have been fired.
Later, the department tweeted that it was clearing floors of the parking garage one-by-one. In a follow-up tweet, it said the search was complete and employees were allowed to retrieve their vehicles.
Dallas Police Chief David Brown applauded officers after the search:
Great job by our officers!
— Chief David O. Brown (@DPDChief) July 10, 2016The department noted that it acted "out of an abundance of caution" to make sure reports of a suspicious person were "thoroughly investigated."
Police in Dallas are still reeling from a massive sniper attack in which a lone gunman killed five officers and wounded several others on Thursday.
It was the largest loss of life by a police department since the September 11, 2001 attacks.
Police officers were also attacked in Georgia and Missouri on Friday.