Jan. 8 — A small fire that broke out Saturday afternoon at the construction site of Boston University’s National Emerging Infectious Diseases Laboratories was easily contained and will not delay work on the lab, BU Medical Campus spokeswoman Ellen Berlin said.

The fire started in a rolling dumpster on the fifth floor of the building and was sparked by a construction worker’s cigarette butt, said Boston Fire Department spokesman Steve MacDonald.

MacDonald said the fire was small and should not be cause for great concern. “These happen all the time,” he said.

The only damage was to the dumpster containing the fire and the construction debris inside. No one was injured, he said.

The biolab has faced fierce local opposition, and federal and state safety reviews of the lab have been deemed insufficient by the Massachusetts Supreme Judicial Court and National Research Council in recent months.

The building is nearly complete and scheduled to open later this year. It will be the site of a controversial Biosafety Level-4 Laboratory which will house some of the world’s deadliest viruses, including Ebola, plague and anthrax.

The university did not issue a statement and Berlin called Saturday’s fire a “very minor incident.”

“Safety at the site is of paramount importance,” she said.