Grenade launcher

A rocket Propelled Grenade, also known as an RPG was an anti-tank weapon poineered by the germans during World War Two.

One was Present at Geheimhaven when Indiana Jones threatened to destroy the Ark. However, Belloq called Indy's bluff and as a result, Indy was captured.

Another was the Soviet RPG present in the jungles of Peru when Indiana Jones destroyed the Jungle cutter.
 * The RPG found in Geheimhaven was an anachronism. RPGs were not invented yet, nor the weapons it was supposed to be, a Panzerfaust.
 * The RPG in Peru existed, it was a Chinese copy, according to Imfdb.