US cases of the novel coronavirus have surpassed six million as many states in the Midwest reported increasing infections, according to a Reuters tally.

Iowa, North Dakota, South Dakota and Minnesota have recently reported record one-day increases in new cases while Montana and Idaho are seeing record numbers of currently hospitalised Covid-19 patients.

Many of the new cases in Iowa are in the counties that are home to the University of Iowa and Iowa State University, which are holding some in-person classes. Colleges and universities around the country have seen outbreaks after students returned to campus, forcing some to switch to online-only learning.