转入地下 meaning in Chinese

underground

The guerrilla force fell in trouble , so they had to go under
游击队陷入了困境，因此他们不得不转入地下。
I was charged with a case from this action and was forced to go underground
由于这次行动我受到指控，被迫转入地下。
Many of the new converts risked their lives , taking their beloved religion underground
许多新皈依的人冒着自己的生命危险，带着自己挚爱的宗教转入地下。