Some 20 climate protesters were arrested Saturday during a runway demonstration at Massachusetts‘s Hanscom Field Airport.

Massachusetts State Police confronted a group of 25 protesters from the group Extinction Rebellion Boston, which was demonstrating in opposition to the airport’s proposal to add 27 more hangars across 47 new acres on the airport’s western side. A portion of the protesters crossed a perimeter to block a runway, which shut down the airport temporarily. The individuals are now facing charges of trespassing and disorderly conduct.