Hundreds of people gathered on bridges in Iran to form human chains following a government call to protect key infrastructure.

Footage shows crowds holding Iranian flags on the White Bridge in Ahvaz and on a historic bridge in Dezful.

The move comes amid heightened tensions, after warnings from the United States over the conflict.

The gatherings took place before Washington and Tehran announced a two-week ceasefire.

Authorities had earlier urged citizens to take part in displays of support.