POLICE shut down Green Lanes in Winchmore Hill this morning after a suspected chemical spill.

A host of ambulances, police cars, fire engine and emergency response units were deployed to the incident on the 329 bus heading to Turnpike Lane.

Initial reports just after 9am suggested a toxic chemical may have been leaked on the bus, and the emergency services treated it as potentially a very serious incident.

However, it soon emerged that a harmless smoke bomb had been let off.

The main road was cordoned off around the junction with Ford's Grove while shocked bus passengers were treated and the source of the alert was determined.

The cordon was taken down at around 10.10am, and the road is returning to normal.