China's major oil suppliers denied there was a rise in oil prices and blamed the rumors for the worsening shortfall in fuel supplies that is spreading northward across the country.

High international oil prices have fueled rumors about price rises in the domestic market and prompted some producers and dealers to hoard oil, worsening the situation, China National Petroleum Corporation and China Petroleum and Chemical Corporation, also known as Sinopec, jointly announced.

The shortage, first reported in southern China, now appears to be spreading to the northern parts of the country.

Shanghai, the country's economic center, is now affected, with rationing, long queues and pumps that are turned off becoming common at filling stations. The Shanghai Economic Commission said on its Website that the city has enough diesel to last more than 10 days.

CNPC and Sinopec emphasized that China had enough oil to ensure a stable supply and the fuel-supply crisis of the second half of last year would not re-emerge.

According to the National Development and Reform Commission, China's top economic planner, refined oil output, mainly produced by the two oil giants, surged 10.5 percent in the first two months of this year. The stockpile rose 28 percent, compared with the beginning of this year.

The two giants said continuing reconstruction of facilities after the recent snow disruptions and spring ploughing have also increased pressure on the supply network.

Industry experts blamed government-controlled prices for the shortfall as refiners cut output to avoid losses.