Iran’s veteran official in charge of oil refining and imports was dismissed on Tuesday, the latest in a series of senior officials who have been removed from their posts in the country’s vital oil industry.

No reason was given for the removal of Mohammad-Reza Nematzadeh, deputy oil minister in charge of the National Iranian Oil Refining and Distribution Company, but analysts see change as part of an attempt by President Mahmoud Ahmadi-Nejad to consolidate his influence over the hugely important sector.