Published: May 18, 2010 10:59 PM EDT

 NEW ORLEANS (AP) - Federal officials say they've expanding the area of the Gulf of Mexico where fishing is shut down because of a massive oil spill.

They had already shut down fishing from the Mississippi River to the Florida Panhandle soon after an offshore oil rig exploded and sank last month. About 7 percent of federal waters were affected.

The National Oceanic and Atmospheric Administration announced Tuesday that it's expanding the closed area, though it won't say exactly where until later in the day.

Nearly 46,000 square miles, or about 19 percent of federal waters, will be shut under the expanded ban. Dr. Jane Lubchenco of NOAA says the government will be testing fish that is caught to make sure it's safe.