Three knives, a machete, a white handkerchief and around 300 rounds of bullet shells were also found on the premises of Holey Artisan Bakery that was stormed by at least five gunmen on July 1, sparking a 12-hour stand-off with police that saw 20 hostages murdered with machetes.
Police also found nine safety pins and suspect these are of the grenades used by the terrorists, the bdnews reported.
A police official said the bloodied handkerchief with something written on it in black ink, was found on a dead body.
Thirteen hostages were rescued when security forces stormed the restaurant.
