Emergency crews are battling a fire at Novo Nordisk's (NYSE:NVO) headquarters in Bagsvaerd, a Copenhagen suburb, the second one in a week.
The Danish pharmaceutical company said that the blaze, which began outside a building, had spread to an adjacent office.
"The fire brigade is present, and the process of extinguishing the fire is expected to last some hours," the company wrote.
NVO shares fell 1.7% in premarket trading.
Fortunately, the smoke is non-toxic, and no injuries have been reported.
The accident comes in less than a week after a fire broke out at a different Novo Nordisk site in Kalundborg, west of Copenhagen.
That happened on the roof of a new building under construction at a manufacturing site where the company is expanding its production capacity for diabetes and weight-loss drugs.