Police on Wednesday arrested four male subjects for suspected involvement in a series of loanshark harassment cases.

Among them were three men believed to responsible for setting fire near debtors' home in Jurong West, Toa Payoh and Tampines since Jan 1.

The men, aged between 17 and 24 were arrested on Wednesday in a seven-hour operation.

They are also believed to be behind more than 10 cases of paint-splattered doors and loanshark graffiti on walls.

On the same day at about 10.55 pm, the police also arrested a man believed to have splashed paint on cars belonging to innocent car owners in Hougang and Senja Link.

Under the Moneylenders' Act (Revised Edition 2010), first-time offenders found guilty of any acts of loanshark harassment face a maximum jail term of five years, a fine between $5,000 and $50,000 and between three and six strokes of the cane.

First-time offenders found guilty of assisting in carrying on the business of unlicensed moneylending may be fined between $3,000 and $30,000, jailed for a maximum of four years, and be caned up to six times.

Head of the Unlicensed Moneylending Strikeforce of the Criminal Investigation Department, Superintendent of Police Aileen Yap said: "Those who deliberately set fire, vandalise vehicles and insult another's religion will be arrested swiftly and dealt with severely in accordance with the law."