SINGAPORE - The two Germans accused of trespassing and vandalising an SMRT train at Bishan depot earlier this month were charged with two more counts of entering a protected place without authorisation on Friday.

Andreas Von Knorre and Elton Hinz, both 21, are said to have entered the depot in Ang Mo Kio Avenue 1 on Nov 6 at 2.43am and the next day at about 2.20am.

They have been charged with entering the depot on Nov 8 at 2.48am and using indelible spray paint to spray graffiti on the left exterior cabin of the train.

Mr Christopher Bridges is representing the pair.

He is overseas and a fellow lawyer John Abraham mentioned the case on his behalf.

Deputy Public Prosecutor Timotheus Koh told the court that the pair face charges with serious consequences.

"They are both foreigners and on social visit passes... no ties, no assets in Singapore and are assessed as flight risk,'' he said.

Bail of $100,000 in one surety or $50,000 in two sureties is offered.

Mr Koh said their passports will remain with the police and that the bailors have to be Singaporeans. Mr Abraham said he understood from Mr Bridges that the pair are likely to "take a certain course'", meaning to plead guilty.

A pre-trial conference is fixed for Dec 17. If convicted of vandalism, they could be fined up to $2,000 or jailed for up to three years plus three to eight strokes of the cane each. The maximum punishment for entering a protected place is a $1,000 fine and two years on each charge.

The incident at the Bishan Depot on Nov 8 was the fourth case of vandalism at SMRT's depots since 2010, and the second this year.