A rift has developed between Russia and Azerbaijan, which have had long political, economic and cultural ties.

The rift, provoked by the deaths of two ethnic Azerbaijanis in Russian custody, was the latest in a series of spats that revealed a deeper diplomatic rift between the former allies.

Authorities in Azerbaijan arrested two journalists from the local branch of a Russian state news agency on Monday in a move likely to further stoke tensions with Moscow following arrests in Russia of ethnic Azerbaijanis suspected of serious crimes.