Authorities have confirmed that 10 people — including a responding firefighter — were injured after a chemical tank imploded at a pulp and paper mill in Washington state. But they declined to immediately say how many workers had been killed or remained missing. In a joint statement, Nippon Dynawave Packaging Co. and local law enforcement said Tuesday that the tank’s rupture caused “multiple critical injuries” as well as fatalities. Authorities said some victims had suffered burns or inhalation injuries. There was no immediate threat to the public. The statement, issued more than four hours after the tank imploded at 7:15 a.m., said crews were continuing recovery operations and that no identifying information would be released about victims pending notification of relatives.