A suspicious package was secured by a bomb squad in Dallas following the shootings and killings of multiple police officers at a Black Lives Matter protest on Thursday night.

Earlier in the evening, Dallas Police Department's Chief David Brown said snipers suspected of killing multiple police officers may have planted a bomb in the city.

The snipers are suspected in the shootings of at least 11 police officers from elevated positions at a Black Lives Matter protest. As of 12 a.m. EDT Friday, four had died. One civilian was also wounded during the protest shootings.

The snipers were believed to have been in a parking garage.

In a news conference Thursday night, July 7, the chief said he needed to quickly return to the scene and help find the bomb, if one were planted. The snipers had made the bomb threat, police said, but it is not clear how the threat was made.

One suspect and one person of interest were in custody just before 1 a.m. EDT.