Myanmar military seized a large cache of weapons on a truck headed for Mandalay this week, after arresting militants following a firefight in the country's second-biggest city, state media reports.

The Global New Light of Myanmar newspaper ran a photograph of four arrested people in front of a weapons cache. It reported security forces had seized more than 100 firearms, 10,000 bullets, 499 grenades, along with explosives and detonators.

According to the state-run media, arrested members of the People's Defence Force (PDF), the armed wing of the National Unity Government (NUG), had confessed to receiving training and obtaining the arms from the Kachin Independence Army (KIA).