GREEN OAK TOWNSHIP, Mich. (AP) — Authorities in Livingston County want to know who put six homemade incendiary devices near a shopping mall, sparking a small grass fire.

The Livingston County Daily Press & Argus and WHMI-FM report the fire burned Monday near Green Oak Village Place mall in Green Oak Township, about 35 miles northwest of Detroit. No injuries were reported from the so-called bottle bombs or the fire, which scorched a grassy area.

The fire and one device were near a newly built home. Authorities say the devices were made from 2-liter bottles and chemicals, and all had exploded.

Two of the devices were found on mall property and three were found in a home under construction. Police were seeking tips from the public in the case.