OTTAWA -- Two large water tanks were found on Highway 17 in Laurentian Valley Township Tuesday night, the latest mysterious objects left in the roadway, prompting a police investigation.

Upper Ottawa Valley OPP said the two tanks were found near B Line Road around 9:30 p.m. Tuesday. A hot water tank and water softener tank were both found on the shoulder of the highway.

No one was hurt in the incident but police believe it's connected to other recent cases of debris being left on the highway between Pembroke and Renfrew. Vehicle rims were left on the roadway overnight Sunday near Sawmill Road in Laurentian Valley, but no one was hurt. Boulders were also found in early January along the roadway, causing damage to cars but no injuries were reported in that incident either.

Police said Tuesday officers were stepping up patrols in the area and are asking residents to be alert on the highway, particularly during the early morning hours.

Anyone with information about any of the three incidents is asked to contact Upper Ottawa Valley OPP at 613-735-0188 or Pembroke/Renfrew County Crime Stoppers at 1-800-222-TIPS (8477). Crime Stoppers also accepts tips online.