Crude prices declined further on Thursday despite an ongoing labor strike in Nigeria.

Nigeria's oil labor unions launched a strike Wednesday against government's price increases on gasoline. However, reports said strikes in Nigeria did not affect oil exports in Africa's largest crude producer.

The U.S. government report on Wednesday showed crude inventories rose last week to their highest level in nine years.

Light, sweet crude for August delivery fell 21 cents to 68.65 dollars per barrel on the New York Mercantile Exchange.

London Brent crude settled down 20 cents to 70.22 dollars a barrel.