Nordic and Baltic seismologists said that they had detected blast-like waves on Sunday when a Baltic Sea gas pipeline ruptured but that the data was not strong enough to determine whether explosives were involved. Authorities in Finland and Estonia, whose state-run companies own and operate the Balticconnector pipeline, have said that the damage appeared to be caused by "mechanical force" and that it may have been a deliberate act. Norwegian seismology institute NORSAR, analysing data collected