South African firm Bumbo International Trust announced a recall of 4 million baby seats warning consumers of a fall hazard, U.S. regulators said. The recall is an extension of a 2007 recall in which 1 million Bumbo seats were recalled to provide consumers with warning stickers about using the seats on raised surfaces. The Consumer Product Safety Commission said the firm has at least 50 reports of infants falling from a Bumbo seat \"while it was being used on a raised surface.\" Nineteen of those incidents included serious injuries, such as skull fractures. The bottom of the Bumbo seats are round and flat. They are constructed of a single piece of molded foam. They were sold in various colors, the commission said. The bottom of the seat includes the words \"Manufactured by Bumbo South Africa material: Polyurethane World Patent No. PCT: ZA1999/00030.\" The back of the seat includes safety warnings. Any seat made since 2008 includes a warning label on the front that warns consumers not to use the seats on raised surfaces. The seats were sold nationwide from August 2003 through August 2012 for $30 to $50. Consumers were advised to stop using the baby seats and to order a free repair kit online at www.recall.BumboUSA.com. Consumers can call 866-898-4999 for information.