Obama: Yemen Terrorist Threat Credible

​At a White House briefing, President Barack Obama just said suspicious packages found aboard two cargo planes bound for the United States "do apparently contain explosive material."

They came from Yemen and were inside Fed-Ex and UPS packages bound for a synagogue in Chicago.

A tip, and not package screening, led to the discovery.

As a precaution, Canadian and U.S. Air Force escorted an Emirates Airlines flight to a runway where authorities searched the baggage hold.

Obama called this "a credible threat" from terrorists, and John Brennan, the assistant to the president for Homeland Security, told reporters it is not presumed the plot is over.

Developing ...