DALLAS (AP) — The pilots' union at American Airlines sued to block the carrier from flying to China and told members not to operate flight there because of the spreading coronavirus outbreak.

The Allied Pilots Association, which represents American’s 15,000 pilots, filed the lawsuit Thursday in state district court in Dallas. The union cited the declaration by international health experts that the virus is a public health emergency.

“I am directing all APA pilots to cease flight operations between the United States and China,” union President Eric Ferguson said in note to pilots.

American did not immediately respond for comment.

Earlier this week, American announced that it will suspend flights between Los Angeles and China beginning Feb. 9 but a union spokesman said the group wants them to be halted immediately, along with flights from Dallas-Fort Worth International Airport.