A German 88-mm anti-aircraft gun (FlaK 18) set up to fire at ground targets in Tunisia; North Africa. 

In ground target role

Crew posing with a 17 cm Kanone 18 in Mörserlafette, probably in a training exercise.
The 17 cm Kanone 18 in Mörserlafette (17 cm Cannon 18 on Heavy Gun Carriage), was a German heavy artillery piece used during World War II. 
 It was of the "double recoil" or dual-recoil carriage, the normal recoil forces were initially taken up by a conventional recoil mechanism close to the barrel, and then by a carriage sliding along rails set inside the travelling carriage. The dual-recoil mechanism absorbed all of the recoil energy with virtually no movement upon firing, thus making for a very accurate weapon.

Heavy artillery

A German 20-mm anti-aircraft (Flak 30) battery, located south-east of Lake Ilmen, Novgorod region of the USSR; August 12, 1942.