Part of a terminal at Detroit Metropolitan Airport was evacuated for more than an hour Thursday morning after a suspicious package was found on its lower level, authorities said.

The package was reported about 9:40 a.m. at a loading dock of McNamara Terminal, the Detroit hub for Northwest Airlines Corp. flights, and a 300-foot radius around the package was cleared, airport spokesman Scott Roberts said.

The check-in, baggage claim and roadway just outside the terminal were evacuated and closed, Roberts said. An explosives team cleared the package around 10:50 a.m. and the terminal reopened about 11 a.m., Roberts said.

Security protocol at the airport, about 25 miles west of Detroit, calls for clearing a 300-foot radius around any suspicious package, Roberts said.

The Transportation Safety Administration and FBI planned to investigate, Federal Aviation Administration spokeswoman Elizabeth Cory said.

The terminal also serves carriers including Continental Airlines Inc. and Delta Air Lines Inc.