( CNN ) -- Rescuers combed through mangled wreckage early Sunday searching for survivors after two passenger trains collided in southern Poland , leaving at least 16 dead . An American citizen was among the dead , said a spokesman with the U.S. Consulate in Krakow . In addition to the fatalities , the collision Saturday night injured at least 60 others , according to the Polish State Fire Brigade . Authorities are `` almost sure there will be no living persons inside the wreckage , '' said Marcin Kopczynski , the duty officer . `` We are using dogs to see if there are any living persons inside but no signs yet . '' A firefighter described the rescue operation at the crash site in Szczekociny as complicated . `` The damage ( to ) the wagons is huge . We have contact with victims . We approach very cautiously , '' firefighter Jaroslaw Wojtasik told CNN 's Polish affiliate TVN . More than 100 passengers who were not injured were evacuated to Warsaw , authorities said . CNN 's Joyce Joseph contributed to this report .
NEW : A U.S. citizen is among the dead , consulate confirms . NEW : Finding more survivors is unlikely , duty officer says . At least 60 people are injured . The rescue operation is complicated , a firefighter says .