A Palestinian gunman opened fire at Israeli troops at a security checkpoint on the outskirts of Jerusalem on Sunday, lightly injuring a Palestinian bystander, police said. The assailant walked up to the Kalandiya checkpoint just north of Jerusalem pulled out a gun and began shooting, Jerusalem police spokesman Shmuel Ben-Ruby said. After firing two shots, his pistol jammed and he was quickly overcome by security personnel at the site. A Palestinian who was at the checkpoint was lightly wounded by shrapnel in the late-afternoon attack. He was treated on the scene by Israeli medics from Magen David Adom, and then evacuated to a Jerusalem hospital for treatment.