A late night traffic accident injured four people in Salem, on Main Street near Alexander Road. Two pickup trucks were involved. Dave Poulson, Salem police chief, says two of the injured were flown to Greenville for medical treatment. Their conditions weren’t known to Poulson by early afternoon yesterday. Poulson says two other persons injured did not require hospital treatment. The cause of Friday night’s accident beyond the 11 o’clock hour remains under investigation.