rtokens: Officials did not immediately identify the victims .
pos: NN NN NNS VBD PRP VBD VBG DT NN IN DT NN CC NN IN DT JJR NNS .
tokens: Fire department officials said they were investigating the cause of the blast and searching for any more casualties .
ltokens: Eyewitnesses told Boston television stations they saw a gasoline truck parked behind the Lilac Falls Motel and smelled gasoline shortly before the explosion .