MOSCOW (AP) -- A Russian airliner crashed south of Moscow, and another passenger jet went missing about the same time after both took off from Moscow, the ITAR-Tass news agency reported Wednesday. There was no word on survivors. Witnesses reported seeing an explosion before the plane crashed, and authorities were not ruling out terrorism, the agency said.A Tu-134 airliner that apparently had 42 people aboard crashed in the Tula region, 125 miles south of Moscow, at about 10:56 p.m. Tuesday, ITAR-Tass reported, citing the Emergency Situations Ministry.A Tu-154 with 44 people aboard went missing about the same time near Rostov-on-Don,...