(Bloomberg) -- Libya’s National Oil Corp. declared force majeure on crude shipments from Zawiya port starting July 20 after halting production from the Sharara oil field, it said in a statement.

Production from Sharara, Libya’s largest oil field, was stopped as a result of a probe into a suspected valve closure, the company said. Production of 290,000 barrels a day has been halted, preventing the loading of crude at the terminal, according to the statement.

“Criminal activity has required NOC to declare force majeure at Zawiya,” NOC Chairman Mustafa Sanalla said in the statement. “Deliberate attempts to sabotage pipelines and production hurt both national oil revenues and critical power supply for everyday Libyans.”

Security personnel and engineers are investigating the incident and working to quickly restore production at the oil field, and authorities will find and prosecute those responsible, Sanalla said.

To contact the reporter on this story: Nadeem Hamid in Washington at nhamid3@bloomberg.net

To contact the editors responsible for this story: Shamim Adam at sadam2@bloomberg.net, Dominic Lau

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