Two robberies and an explosion took place on campus this week, according to Harvard University Police.

A chemical experiment went wrong at the Mallinckrodt Laboratories on Oxford St. last Friday, causing an explosion that shattered glass and injured an employee. The employee, whose name and present condition could not be determined yesterday, was taken to Cambridge Hospital. The lab itself was not visibly damaged.

Thieves stole cameras and jewelry worth more than $300 from a Dunster House room last Monday afternoon, though police found no sign of forced entry.

"We think it was someone with a key," said one resident, adding that "there are a lot of master keys floating around" because they are available to student dorm crew workers.

The second larceny involved the theft of computer equipment worth more than $6400 from an unlocked room at the School of Public Health. An IBM computer, monitor, and printer were reported missing last Friday. Harvard police said they have no suspects.