BAGHDAD- A mortar attack on an Iranian dissident camp killed three people in Baghdad on Saturday, police sources said, and the Mujahidin-e-Khalq (MEK) group said Iran was probably to blame, with Iraqi complicity.MEK said two of the camp's residents were killed and 40 wounded in the attack. An Iraqi died when a stray mortar round hit a residential complex for Baghdad airport employees nearby.A similar attack on the camp in February killed at least five members of the MEK, which was removed from the U.S. State Department's list of terrorist organizations last year.