Dutch police arrested two more suspects Friday in connection with a drug lab found inside a home in The Hague’s Segbroek neighborhood.

The new arrests were a 44-year-old man from The Hague and a 71-year-old man from Leiden. Officers had already detained two other men Thursday.

Police discovered the lab Thursday afternoon after a resident reported a strange odor. Inside the house, they found a working drug lab and barrels holding thousands of liters of chemicals. Investigators have not yet identified what drugs were being made.

A 39-year-old man from The Hague was inside when officers entered. He tried to flee, slipped in the liquids on the floor and was arrested. He was taken to a hospital for checks. Later Thursday evening, police arrested a 34-year-old man from Voorburg.

The discovery forced about 200 neighbors to evacuate. They were sheltered at the district office and returned home by the end of the evening.