China's producer price inflation grew to 5% year on year in April, the National Bureau of Statistics reported. In March the annual Producer Price Index was 3.9% up on the year before and in February it was 3.5% higher. Raw material prices rose 6.2% from 2003, with crude oil climbing 3.8% and steel rod prices gaining 35%. Analysts said the growth in producer prices, the price of goods at the factory gates, was driven by a surge in investment in factories and rising energy and raw materials costs. They said the increase will likely add to pressure on authorities to raise interest rates to protect consumer prices.