def get_indels_regions(read):
    """Get indel region start and end positions of a read."""
    indels_blocks = []
    aligned_regions = read.get_blocks()
    start = read.reference_start; end = read.reference_end
    indels_blocks.append((start, aligned_regions[0][0]))
    for i in range(len(aligned_regions)-1):
        indels_blocks.append((aligned_regions[i][1], aligned_regions[i+1][0]))
    indels_blocks.append((aligned_regions[-1][1], end))
    return indels_blocks