HOUSEHOLDS using piped gas will have to pay 1.87 cents per kWh from this Friday, which will add $1.70 to their monthly gas bill.

City Gas, announcing the tariff increase, blames 'substantial increase in fuel oil price' as a reason for the hike. The current increase represents a 9.7 per cent hike from the current 19.34 cents per unit.

The last hike was in February this year when tariffs went up by about 7 per cent. City Gas supplies piped gas to 90 per cent of residents living in new HDB  estates and private properties, as well as commercial operations like hawker centres and hotels.