The sinkholes have emerged in Sao Lam Hamlet, Thanh Son Commune, following prolonged heavy rain in June and July, according to the provincial Department of Agriculture and Environment.
Two of the sinkholes, measuring 1-2 metres in diameter and up to 1.5 metres deep, have been filled. A third, located in a residential garden, remains active. It is 2.5-3 metres wide and up to 2 metres deep, with signs of continued subsidence.
The sinkholes caused the collapse of a household's boundary wall and cracks in nearby houses and courtyards, with some cracks continuing to widen.
The cause has yet to be determined, with initial assessments pointing to karst geology, groundwater fluctuations or underground erosion.
Warning signs and barriers have been erected around the affected area, while local authorities have restricted access and banned heavy trucks from using the damaged road section.
Residents in the affected area have also been advised to suspend groundwater extraction and new permanent construction until further geological surveys are completed.
The subsidence has directly or indirectly affected 11 households, according to local authorities, who are preparing evacuation plans should conditions deteriorate.
Local authorities have proposed hiring geological experts to investigate the cause and recommend long-term mitigation measures.