<sod >ÃÂÃÂ  There was no immediate word on what caused the blast Tuesday at the plant in Baumgarten an der March, east of Vienna, where pipelines connect and gas is compressed.< eod>< sod > ÃÂÃÂ  A further 18 people were injured in the morning blast at the plant in Baumgarten an der March, east of Vienna, regional Red Cross official Sonja Kellner said.< eod>