A laboratory in Sudan was seized by warring parties, causing concerns about biohazardous materials.

The World Health Organization’s representative in Sudan’s capital Khartoum, Nima Saeed Abid, said that the major concern is there is “no accessibility to the lab technicians to go to the lab and safely contain the biological material and substances available,” per Reuters.

At least 459 people have been killed in the fighting, according to Reuters.

A cease-fire truce was declared Tuesday, yet residents say some fighting and shelling has continued between the Sudan Armed Forces and the Rapid Support Forces.

The lab has polio isolates, measles isolates and cholera isolates stored.

“There is a huge biological risk associated with the occupation of the central public health lab in Khartoum by one of the fighting parties,” Saeed Abid said, per CNN.

Power cuts in the area are also a cause of concern because of the need to keep blood bags cold in order to be used.

A medical source expressed worries to CNN that “the danger lies in the outbreak of any armed confrontation in the laboratory because that will turn the laboratory into a germ bomb. ... An urgent and rapid international intervention is required to restore electricity and secure the laboratory from any armed confrontation because we are facing a real biological danger.”

Sudan evacuations

Earlier this week, U.S. diplomats and their families were evacuated by military aircraft out of Sudan. “All 70 staffers were reported safe,” USA Today reported.

Other countries followed suit, airlifting their citizens from the Sudan. The first evacuation of U.K. citizens involved a military flight that landed in Cyprus Tuesday.

Djibouti is operating as a hub for evacuations for diplomats and foreign nationals trying to leave the country, per BBC.