Pro-government activists have stepped up a campaign of intimidation against Catholic priests who have been helping organise environmental protests on the north-central coast.
A CCTV camera showed young men throwing rocks at Van Thai Church in the Quynh Luu District of Nghe An province on Wednesday night.
A large posse of men on motorcycles had earlier circled the area, flying the national flag and shouting threats at would-be protesters.
Some of them strung a banner across the road demanding the expulsion of two priests, Dang Huu Nam and Nguyen Dinh Thuc, who have played a leading role in protests over last year’s environmental disaster.
The authorities have stepped up their campaign against the protest movement, arresting a number of bloggers, breaking up demonstrations and unleashing civilian thugs to intimidate government critics.
Villagers in some coastal regions of Nghe An say they have not received adequate compensation for last year’s disaster which devastated fish stocks along the north-central coast.
Fishing is still restricted in a number of areas because of residue from the toxic leak at the Formosa steel plant.
State media have accused the priests of stirring up discontent and defaming the authorities because of their role in organising protests and demands for compensation.
Last month the police arrested a prominent government critic, Hoang Duc Binh, for his reporting on the protests.
He has been charged with “abusing democratic freedoms”, a charge often used to silence dissent and which leads to lengthy prison terms.
Mr Binh had worked with the priests in their campaign to raise awareness for the environmental cause.