Reuters: Shots were fired from what was described as an armoured van in an attack on Dallas Police headquarters early on Saturday, police said, and an explosive device was found outside the building.
Dallas Police Chief David Brown told reporters that a motive for the attack was not yet known. The device later exploded as a police robot attempted to move it.
He said witnesses said as many as four suspects were involved in the incident, which began around 12:30 a.m.
No officers have been injured, but one suspect, who has been speaking with police, said he had been hurt, Brown said.
The police chief said when police responded to reports of automatic gunfire, the van rammed a squad car and at least one person began shooting. The van drove off when the police returned fire and the police gave chase, Brown said.
The van stopped in a fast food restaurant parking lot in the city of Hutchins, some 10 miles (16 km) south of Dallas, where there was another exchange of gunfire.
Brown said police negotiators had been in contact with one of the suspects inside the van, who identified himself as James Boulware.
The police chief said they had yet not been able to confirm the identity of the man, but Brown also said that police had responded previously to three incidents of domestic violence involving a man with that name.
Brown said that the suspect had said that police had taken his son and had accused him of being a terrorist. The police chief said that the man then threatened to "blow us up."
Four bags were found scattered around police headquarters, at least one of which had explosives inside, Brown said. It was one of these bags that later exploded when a police robot attempted to move it, police said.
Police said another suspicious package was found under a police truck in the police headquarters` parking lot in addition to another one in a dumpster near a different police station in the city.
Nearby residents were evacuated, Brown said.
A video of the incident on social media showed a police officer approaching a black van with a flashlight as two other police cruisers pulled up behind the vehicle. The officer then abruptly turned and ran away and then a volley of gunshots could be heard.
In another video, the van could be seen ramming a police cruiser before gunfire rang out and the vehicle drove off.
