Bahraini authorities announced they arrested four Iran-linked terrorists over having a hand in November's blast that targeted a state-run oil pipeline.
The attack targeted a gas pipeline near the Shiite village of Buri. No casualties have been reported.
A statement from the Bahraini Interior Ministry said two of the assailants received "intensive training" in Iranian Revolutionary Guard (IRGC) camps in Iran.
Iran is widely known to be behind Shiite insurgents in Bahrain.
In 2017, Bahrain announced the detention of Shia clerics working to destabilize the country's internal stability.
The government named four suspects, saying one of the men already faces a 15-year-sentence in another case.
The detainees range in age from 23 to 27 years old.