Massachusetts officials are stepping up warnings about the potential for roofs to collapse under the weight of snow that has built up in recent weeks.

Public Safety Commissioner Thomas Gatzunis said Tuesday that owners of residential and commercial buildings should be aware of signs of stress on roofs, including ceilings that are sagging or developing cracks.

Other signs could include popping or cracking sounds from the roof or attic area, and doors or windows that either won't open or suddenly open on their own.

Numerous partial roof collapses have been reported in the state but no serious injuries to date.

While most of the snow has fallen so far has been powdery, Gatzunis says any rain or wet snow in the future could dramatically add to the weight on roofs.