HELSINKI — Swedish emergency services say that a huge sinkhole in northern Sweden has forced the closure of a factory in an industrial area and halted boat traffic on a nearby river.

Hakan Wiberg from the Ornskoldsvik emergency services says they had cordoned off the area for fear of further erosion after the hole grew to a size of eight-by-eight meters (26-by-26 feet).

Workers at a forest products refinery on Sunday evening alerted emergency services to the hole, which was apparently caused by a burst underground sewage pipe.

It was not clear if the hole had caused any damage to buildings but experts were investigating the area on Monday.

No further details were immediately available.