An Indian-origin lawyer with apparent Nazi sympathies went on an early morning rampage in US' Houston city shooting nine people on Monday before he was killed by police, according to authorities.

Nathan Desai was wearing military-style clothing with Nazi symbols during the 20-minute shooting spree when he fired at passing cars.

Police said that they did not know why Desai went on the rampage hitting people at random.

Desai's name was written with the 's' capitalised in media reports in Houston, making it sound European, but his father was identified as Prakash Desai.

All of his victims survived but one person was critically wounded and five were hospitalised, Houston's Acting Police Chief Martha Montalvo said.

She described the shooter as a lawyer who was having problems at his law firm. When police responded to the shooting, he shot at them and was killed when police returned fire, Montalvo said.

The shooter's father, 80-year-old Prakash Desai told KPRC TV that his son was "worried" because his law practice was not doing so well.

Forty six-year-old Nathan Desai owned several guns to protect himself against his clients, some of whom were "funny people and criminally-minded people", his father said.

Houston Chronicle said that Prakash Desai is a retired geologist.

The daily reported that police found in his flat several military items that went back to the Civil War.

Police found a Thompson submachine gun in his Porche and a 0.45 caliber handgun that he used against the police.

The Chronicle said that police used a robot to examine his car and his flat for explosives.

This is the second mass shooting by a person of Indian descent in the US.

In 2003, at the Case Western Reserve University in Cleveland, Biswanath Halder went on a rampage, taking hostages, killing a graduate student and wounding another and a professor.

A graduate of the university's business school, he unsuccessfully sued a university administrator.

He was captured alive and sentenced to life after a trial.

Although it was not a mass shooting incident, in January 2016 Mainak Sarkar caused a lock down at University of California at Los Angeles when he killed a professor there. He had also killed his wife and committed suicide.