The music industry is to extend its copyright war by taking legal action against websites offering unlicensed song scores and lyrics.

The US Music Publishers' Association (MPA), which represents sheet music companies, will launch its first campaign against such sites in 2006.

MPA president Lauren Keiser said he wanted site owners to be jailed.

He said unlicensed guitar tabs and song scores were widely available on the internet but were "completely illegal".

Mr Keiser said he did not just want to shut websites and impose fines, saying if authorities can "throw in some jail time I think we'll be a little more effective".