Three people were killed Wednesday in a series of shootings in the Houston area that authorities believe are linked to a gunman who later died by suicide.

The shooter has not been identified. A Houston police official told reporters that the man`s description and vehicle - a silver Ford Escape - connect him to the killings.

The victims have also not been identified.

The first shooting was reported shortly before 1 p.m. in Sugar Land, a city southwest of downtown Houston, the police department said in a statement.

Officers found a woman with several gunshot wounds in the driver`s seat of a white SUV that had gone off the road, according to the statement. The shooting was initially believed to have been motivated by road rage, but investigators determined the gunman had been in a relationship with the victim, police said.

The woman was pronounced dead at a hospital, the statement said.

The statement did not provide additional details about a possible motive and said investigators were still working to understand a potential link to the Houston shootings.

Roughly 30 minutes later and 6 miles away, at an auto shop southwest of downtown Houston, the gunman shot a mechanic after an altercation, Houston Police Lt. Larry Crowson said at a news conference.

"We just know that the guy involved in the shooting there in Sugar Land drove to this location, went to the mechanic shop," he said.

As the shooter was leaving, someone from a nearby warehouse started recording, Crowson said. The gunman opened fire, killing the witness, he said.

Officers responding to a report of a nearby shooting found the man dead of a self-inflicted gunshot wound inside the SUV, Crowson said.

A motive in the second shooting was unclear, he said.