Seven people have been arrested in Vietnam, for bombing a police station in Ho Chi Minh City last month in a rare attack that injured three people.
The bomb was planted on a motorcycle and blew out the glass facade of the building near the site of violent protests over a proposed economic law just days before.
Two officers and a cook were injured in the explosion.
Officials Thursday did not make a direct connection to the protests and said only that it was a carefully orchestrated attack by alleged terrorists connected to a “foreign” group.
“The organisation of the attack… was with support from outside forces,” HCMC Police Colonel Nguyen Sy Quang told reporters Thursday, without naming the alleged group.
“They had careful preparation and had tested explosives many times,” he added.
Three of the men face terrorism charges, while another four face charges of providing explosives. At least three others are being sought in connection with the attack.
Authorities also seized dozens of detonators and 10 kilograms (22 pounds) of explosives that the group allegedly planned to use for further attacks.