A mothers’ search brigade for missing persons in Sinaloa had to flee a clandestine gravesite Tuesday when a gunman began firing at them.

However, the Sabuesos Guerreras (“Warrior Sleuths”) collective did not let the danger stop them. They returned with a police escort and ended up discovering four makeshift graves on Wednesday.

The collective was searching an empty lot in the remains of an abandoned hog farm in Culiacán and had just found what they believed to be a gravesite when shots suddenly rang out.

The women were forced to drop their digging tools and run, seeking refuge at a nearby gas station where they called authorities for aid.

When they finally returned later that day, escorted by local, state and federal authorities and representatives from the National Search Commission, they found that their tools had been stolen and were forced to abandon their search temporarily. However, when they returned the following day, they found four graves.

The group continued their search at the site Thursday, believing there could well be more.

The group, which leader María Isabel Cruz Bernal formed three years ago after her municipal police officer son went missing three years ago, is a group of 370 women with missing family members. They say they search for their loved ones because if they don’t, no one else will.

Once a week, even on holidays, the group goes to sites throughout Sinaloa to search for potential gravesites. They maintain a Facebook page where they solicit anonymous information via a telephone tip line.

Sinaloa holds the unenviable top spot for the most clandestine graves discovered in any Mexican state.

Sources: Milenio (sp), El Universal (en)