A toxic cloud that formed Thursday triggered a public scare that forced the evacuation of offices in Buenos Aires and the suspension of metro and train services in a tourist area.

Security Secretary Sergio Berni said the situation had since been brought under control.

The incident took place after a shipping container loaded with pesticides caught fire at a port in the Argentine capital, causing a thick cloud of smoke -- with a a foul smell similar to gas -- to spread across nearly all of central Buenos Aires.

Civil defense authorities had asked residents in downtown Buenos Aires and the district of Retiro, near the port, to "remain inside with doors and windows closed, and to turn off air conditioners." Many pedestrians in the city protected their faces with scarves or masks.

The scare disrupted traffic during rush hour.

But about three hours after the cloud formed, Berni told reporters "the situation is totally controlled."

"It was a pesticide made from a solid carbonate with low hazard."