FLINT, Mich. — Members of the Michigan National Guard began arriving in Flint on Wednesday for briefings on the drinking water crisis just as state health officials reported a spike in Legionnaires’ disease cases in the county where the city is located.

Gov. Rick Snyder had activated the National Guard late Tuesday, and Lt. Col. William Humes confirmed about a half-dozen representatives arrived Wednesday morning. They are part of a larger contingent of Guardsmen who will help distribute bottled water, filters and other supplies to residents.

Flint’s tap water became contaminated with too much lead after the city switched its water supply in 2014 to save money while under state financial management. Local officials first declared a public health emergency in October in response to tests that showed children with elevated levels of lead.

“I’m glad the state is putting in resources and we welcome the Michigan National Guard with open arms,” Flint Mayor Karen Weaver said in a statement. “However, we also need federal assistance as we continue to cope with this man-made water disaster.”

Meanwhile, Michigan’s Department of Health and Human Services said Wednesday that there’s been an increase in Legionnaires’ disease cases during periods over the past two years in Genesee County.

Legionnaires’ disease is a type of pneumonia caused by bacteria that infect the lungs. Health officials say they can’t conclude that the increase is related to Flint’s water crisis.

There were 45 confirmed cases, including seven associated deaths, in Genesee County from June 2014 to March 2015. In 47 percent of the cases, the water source at the primary residence was from the Flint River. A comparative chart that officials provided shows only 21 cases were confirmed in all of 2012 and 2013.