Officers are at the scene and there's a 100m cordon in place - people are being told to avoid the area.
An evacuation is being carried out, it says.
Officers have evacuated an area of the city while they assess the auto.
Part of Manchester's been evacuated after police found a auto that could be significant in the investigation into last week's concert bombing.
Officers have attempted to track Abedi's movements from May 18, when he returned to England from Libya, through the bombing on May 22. "The auto is a white Nissan Micra".More news: Seattle police fatally shoot pregnant mother of four Charleena Lyles
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Mr Buckley was off duty and waiting for his 15-year-old daughter Stephanie when the bomb exploded at the Ariana Grande concert.
Meanwhile, Abedi's cousins have claimed the 22-year-old plotted "secretly to himself" before the atrocity on 22 May.
Tasha Hough shared two more photos of Jaden, adding: "I think she's a little star struck".
'This is why we are tracking his movements so carefully'.
Ten men remain in custody for questioning and eight people have been released without charge, Greater Manchester police said.
As part of the investigation, authorities are also asking the public to help track down a blue suitcase Abedi was seen with in the days leading up to the attack.