FourSikh men from Punjab have drowned in a cow dung tank on a dairy farm near Paviain northern Italy.

Investigatorssuspect that the four were overcome by carbon dioxide fumes from the cowmanure. They believe that three died after jumping in to rescue a worker whohad been emptying the tank.

Twoowned the farm and two were employees. All were Indian citizens. The twobrothers Prem and Tarsem Singh registered their farm in 2017.

Itis about 45km (28 miles) from Milan.

Italianmedia report that the Singhs' farm at Arena Po, producing milk and veal cattle,is one of the biggest in the Pavia region.

Thevictims were named as: Prem and Tarsem Singh, aged 48 and 45 respectively,Arminder Singh (29) and Majinder Singh (28). The manure was being collected foruse as fertiliser on the farm's fields.