40,000 Iranian Pasdaran attempted to breach the last line of defense protecting access to Basra.

The Iranian offensive failed as the Iraqis were trained in defensive combat and had stronger firepower.

On April 9 and 12 the Iranian government, against past principles, tried to win the battle using chemical weapons.

At nightfall Iranian artillery poured phosgene gas in the Iraqi 3rd Army Corps' sector.

These bombings caused only minimal Iraqi losses of 20 dead and 200 wounded, and did not break the defensive layout around Basra.