Saudi Arabia says it has executed six Iranian men over drug smuggling, sparking strong objections from Iran at a time when the two countries are trying to mend relations.

Tensions resurface in the Middle East as Iran summons Saudi Arabia’s ambassador in a heated diplomatic protest. Accusations of violations and unresolved grievances hint at cracks in their fragile reconciliation.

The Iranians were put to death in Dammam, on the kingdom's Gulf coast, for having "clandestinely introduced hashish" into Saudi Arabia.