Methods and circuits detect a burst error in a block of data bits. Coset calculator circuits calculate coset leaders from a syndrome generated from the data bits of the block. The coset calculator circuits calculate the coset leaders for each frame of the data bits. For each frame, comparator circuits input a corresponding coset leader of the coset leaders. Each comparator circuit determines, for each burst-length portion of one or more burst-length portions within the corresponding coset leader, whether the coset bits of the corresponding coset leader are zero except for the coset bits within the burst-length portion. An error-locator circuit outputs an error vector describing the burst error in the block in response to one of the comparator circuits determining that the coset bits of the corresponding coset leader are zero except for the coset bits within one of the burst-length portions within the corresponding coset leader.