Iran faces serious consequences after protesters stormed two British diplomatic compounds in Tehran, Foreign Secretary William Hague said on Tuesday, adding that he had protested in the strongest terms to Iran's foreign minister.

We hold the Iranian government responsible for its failure to take adequate measures to protect our embassy, as it is required to do, Hague said in a statement. Clearly there will be other, further, and serious consequences.

Hague said all embassy staff and their dependants had been accounted for. Earlier reports said six British embassy staff were briefly held hostage during the incident.

(Reporting by Mohammed Abbas; Editing by Peter Graff)