Mortar

A Mortar is a support weapon used by many armed forces around the world. Mortars are medium range artillery weapons.

Call of Duty Series
They are seen throughout the Call of Duty series, and are usable in Call of Duty 3, Call of Duty: World at War (Nintendo DS), Call of Duty: World At War. They are unusable in Call of Duty 4: Modern Warfare and Call of Duty: Modern Warfare 2. In Call of Duty 4, mortars are used by the Ultranationalists in the level Heat; they target the player's position near the church, mistaking the S.A.S. team for a much larger force. In Call of Duty: World at War for PC and Consoles, Mortar Shells are usable in the level "Breaking Point". The player must throw the mortar shells by hand to destroy other mortar pits. They are extremely powerful and if thrown into the close vicinity, will most likely kill the player. They are found in the various mortar pits the player must clear, resting on top of crates. They can also be used to destroy certain buildings. In the level Burn 'em Out, the player must clear three mortar pits using a flamethrower. Once they are destroyed, the friendly tanks can advance.

Mortar pits are also seen in Blowtorch and Corkscrew and Little Resistance. They are not found in missions that take place on the Eastern Front. In Call of Duty: Modern Warfare 2, they only appear in the level "Loose Ends", where they are used by enemy Ultranationalist forces.

Trivia

 * It is strange that the Marines never used mortars in the Pacific, during the events of Call of Duty: World At War.
 * Presumably, the Artillery Strike is mortars, howitzers or tank destroyers.