Updated

A Texas-based group involved in searches for missing persons around the nation has filed a lawsuit asking a federal court to set aside an order prohibiting the nonprofit organization from employing drones in its work.

A fleet of four unmanned model aircraft used by Texas EquuSearch has been grounded by the Federal Aviation Administration until the agency develops rules that allow for the commercial use of unmanned aircraft.

The lawsuit filed on Monday in a Washington, D.C., appeals court says there is no basis in law to prohibit the operation of model aircraft for humanitarian search and rescue activities.

FAA spokesman Lynn Lunsford says the agency did not have an immediate response to the lawsuit.

The FAA ordered Texas EquuSearch in February to stop using drones in its searches.