A Burger King (BKW) spokeswoman told CNNMoney on Thursday that 5,000 of its restaurants are participating in its new program, called Burgers at Breakfast, which has started to roll out.
The new menu includes a variety of Whopper sandwiches, cheeseburgers and chicken sandwiches as well as French fries and apple pie.
This is the latest salvo is the fast food breakfast wars. Burger King competitor McDonald's (MCD, Fortune 500) does not have hamburgers on its breakfast menu, but the company has considered expanding its breakfast menu hours to try and correct a slump in sales. McDonald's also wooed customers during breakfast hours last month with free coffee for two weeks.
Taco Bell starting serving breakfast in March and introduced the Waffle Taco, a breakfast sandwich wrapped inside a waffle with syrup.
Burger King is also testing a Chicken and Waffle Sandwich.
Meanwhile, fast food workers are preparing to strike in 150 cities.