A massive dust storm engulfed the southwestern US city of Phoenix late Tuesday, blotting out the sun and knocking down electricity poles, local media reported.

The ABC 15 news outlet said the billowing cloud stretched 60 miles wide and packed winds of 60 miles per hour (96 kilometers per hour). There were no immediate reports of casualties or of damage to homes or businesses.

The US National Weather Service confirmed that a "very large and historic dust storm" had moved through the area, without providing further details.

Photos and videos on several local news websites showed a mountain of dust drifting over the city. The storm had reportedly passed by late Tuesday night.

This year unusually severe storms have battered the United States, which is experiencing its deadliest tornado season in six decades and has also seen epic flooding along the Mississippi River and severe drought in the south.