Crude prices have fallen amid increasing supply glut as well as weakening Chinese equities.
Brent crude for October fell 75 cents to $48.86 a barrel on Monday. US oil for October plunged 70 cents and was traded $45.35 per barrel.
Crude prices have declined nearly 60% since June 2014 over a global supply glut.
Also, the prices have fallen in recent weeks amid concerns over the turmoil in the world’s second largest economy, China.
Chinese stocks plunged nearly 12 percent back in August, causing turmoil in the global stock markets.
China is seen as the second largest oil consumer after the United States.
Meanwhile, British authorities announced that the year-long decline in oil prices have already taken a heavy toll on the jobs in Britain's North Sea oil and gas sector.
They say the sliding prices have caused more than 5,000 job losses since late last year.