UPDATE: The M4 has reopened following this incident. People are being told to return to their vehicles.
Police have partially closed the M4 following ‘reports of pedestrians’ on the network.
Traffic officers blocked the westbound carriageway between junctions 14 and 15 at around 9pm today (Saturday).
Delays are building in the area – with National Highways asking motorists to “approach with care”.
A spokesperson said: “The M4 is blocked westbound between J14 (Hungerford) and J15 (Swindon) due to an ongoing Wiltshire Police-led incident.
“Please approach with care as delays are beginning to build.”
Several police vehicles, including what was described as a ‘riot van’, were spotted racing past the stationary traffic.
A police helicopter is circling the Junction 15 area, but it’s unclear if it relates to this incident.