Jamaica's mixed relay team earned the country's second medal in the Mixed 4x400m relay final at the IAAF World Championships.

The quartet of Tiffany James, Roniesha McGregor, Javon Francis and Nathon Allen took silver in a new national record of 3:11:78.

The United States won gold in a new world record time of 3:09:34 seconds.

Bahrain came third in 3:11:82.

- Daniel Wheeler