Cordon is in place while chemical is identified. Ambulance staff are treating nine people.
M6 closed in both directions between J3 A444 / B4113 (Nuneaton / Bedworth / Coventry) and J4 M42 / A446 (Coleshill), congestion on M6 to J2 M69 / A46 (Coventry) Northbound.
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It will be a dry and bright start, however scattered showers will develop.
Rather cloudy, with some rain likely at first.
It's believed there were around 8,000 people who laced up for this year's 10k race.