QUITO, Oct. 20 (Xinhua) -- An Ecuadorian national who survived a U.S. bombing of a submarine suspected of carrying drugs in the Caribbean Sea has been released, local media reported Monday, citing the Attorney General's Office.

The survivor arrived in the coastal city of Guayaquil on Saturday after being repatriated. He underwent a medical evaluation before the start of legal proceedings.

Anti-narcotics officers presented the case to prosecutors, but the Attorney General's Office announced that there were no grounds for his detention since "no crime has been reported within Ecuadorian territory."

U.S. forces intercepted and destoryed the submarine near Venezuela's coast on Thursday, suspecting it was transporting illegal narcotics.

U.S. President Donald Trump later said on social media that intelligence had confirmed the presence of "fentanyl and other illegal narcotics" on board.

Of the four crew members, two died in the attack, while the other two --- one Ecuadorian and one Colombian -- survived and were repatriated for legal processing in their home countries.

Ecuadorian authorities have not released further details about the case. ■