Police have arrested two teens for their suspected involvement in loanshark harassment following a tipoff from the public.

The 14-year-old male and 18-year-old female, believed to be Singaporeans, were behaving suspiciously outside a flat in Compassvale Street in Sengkang on Saturday at 9.50pm when the police arrived.

Two mobile phones, a marker and a piece of debtor note were seized from the suspects, believed to have splashed paint on the doors of debtors and left behind notes demanding repayment in Ang Mo Kio.

They will be charged in Court tomorrow for alleged loanshark harassment. First-time offenders acting for unlicensed moneylenders may face up to five years of jail, a fine of between $5,000 and $50,000, and three to six strokes of the cane.

Unlicensed moneylending and loanshark harassment cases have been on the decline since tougher actions were introduced. They fell from a high of more than 18,000 cases in 2009 to about 8,300 cases last year. Harassment cases with damage to property fell by almost one third, or 2,461 cases, over the past year.

The use of closed-circuit television and police cameras in more than 2,000 HDB multi-storey carparks and residential blocks have helped with police surveillance. The community also chipped in. Nearly 10,000 volunteers have been patrolling their own neighbourhoods and promoting a greater sense of vigilance.