A robber allegedly managed to hold up two Israeli banks by pretending an avocado he was holding was an active grenade.

Both incidents occurred last month in Beersheba in the country’s south and involved the 47-year-old unidentified robber making off with more than AU$12,000, between two robberies a week apart.

According to The Times of Israel, the man handed bank staff a note which read “Hand over the money in the drawer”.

An Israeli man was arrested after allegedly using an avocado to rob two banks by pretending it was a grenade. (Getty / AAP)

The man was allegedly disguised in a hat, sunglasses and an eyepatch and told staff “Put the money in the bag or I will quickly throw the grenade”, showing them the fruit which was painted black.