Dozens of Nigerian protesters have blockaded at least two oil production sites in the country's Niger Delta region, in an apparent protest over jobs.

Officials from the Royal Dutch-Shell oil company say Kula villagers forced oil workers at one of its sites to stop pumping fuel. They say the takeover cut daily production of 70,000 barrels of oil.

The protesters also blockaded a site in the area operated by U.S.-based company Chevron-Texaco.

Some Kula leaders apparently called the demonstration to demand the companies give more jobs to local villagers.

(Some information for this report provided by Reuters.)