A disgruntled warehouse driver killed eight people and himself, and wounded others in a shooting rampage today, company and state officials said.

Authorities in Manchester, Connecticut, were notifying victims' relatives before confirming the number of deaths, state police Lt J Paul Vance said.

The driver had worked at the beer distributor for a couple of years and had been called in for a disciplinary hearing, said John Hollis of the Connecticut Teamsters labour union, who was with company officials at the scene of the shooting.

Hollis would not say why the driver was being disciplined but he had been asked to resign from his job.

About 50 to 70 people were in the warehouse during a shift change when the gunman opened fire around 7am, said Brett Hollander, director of marketing at Hartford Distributors. Adding to the chaos was a fire at the warehouse, about 10 miles east of Hartford, that was put out.

Hollander, whose family owns the distributor, said he did not know the driver well.

At least one person died at Hartford Hospital, spokeswoman Michaela Donnelly said. Another victim taken there was in critical condition, and one was in fair condition, she said.

Among the victims was Hollander's cousin, a vice president at the company who was shot in the arm and the face. Hollander said he thought his cousin would survive. It was not clear if he was among the victims taken to Hartford Hospital.

Police officers from numerous agencies and police and fire vehicles surrounded the warehouse, on a tree-lined road in an industrial park just west of a shopping centre.

Families of workers gathered at the town high school to wait for information and comfort each other.