(Reuters) - Georgia Governor Nathan Deal issued a mandatory evacuation order on Thursday for the state s coast, including historic Savannah, as deadly Hurricane Irma rolled toward Florida and the southeastern United States. The evacuation order for areas east of Interstate 95 and some areas to its west takes effect Saturday at 8 a.m., Deal said in a statement. The governor also authorized up to 5,000 Georgia National Guard members to respond to the storm and expanded a state of emergency to 30 southeast Georgia counties. The order affects the cities of Savannah and Brunswick in Georgia, which has not been hit by a Category 3 hurricane or higher since 1898, according to WSB-TV.  I encourage all Georgians in our coastal areas that could be impacted by this storm to evacuate the area as soon as possible,  Deal said in a statement. Irma, one of the most powerful Atlantic storms in a century, plowed past the Dominican Republic toward Haiti on Thursday after devastating a string of Caribbean islands and killing at least 10 people. Irma will likely hit Florida as a powerful Category 4 storm on Sunday, with storm surges and flooding beginning within the next 48 hours, according to the NHC. Gas shortages in the  Miami-Fort Lauderdale area worsened on Thursday, with sales up to five times the norm. The storm s exact path is uncertain, but it could affect Georgia and the Carolinas early next week. 