TOXIC fumes engulfed the sky during a suspicious blaze in a dry field.

Firefighters were faced with a battle against time to extinguish flames that threatened to spread to nearby shrubland in Sidcup on Tuesday lunchtime.

Thick black smoke could be seen beside the London-bound A20 carriageway at around 12.30pm. The source was a pile of tyres that had been dumped and apparently set alight on private land underneath the flyover.

It was originally feared that the nearby Tesco store in Edgington Way or the Coca-Cola factory in Cray Road were on fire when London Fire Brigade was alerted to the blaze.

Crews from Sidcup fire station were first on the scene and had to find a way to get to the source of the fire behind Ruxley Lakes in Edgington Way.

Fifteen firefighters spent more than two hours dealing with the fire.

Sidcup watch manager Neil Simpson, said: "The crews will stay to make sure the fire is completely put out as fires of this nature have been known to reignite."

The cause of the fire is under investigation . It is the second suspicious fire at the same location in six months.