DENVER (CBS4) – Robbers are targeting mail carriers in the Denver metro area and the U.S. Postal Service has put up a $100,000 reward.

The first robbery took place a week before Christmas in Denver’s Park Hill neighborhood. Two men with knives held up a postal worker and stole mail.

There was another attack on Christmas Eve in Englewood. A carrier was robbed at knifepoint, but investigators do not think the cases are connected.

(credit: CBS)