The incident occurred while equipment was being transferred from England's pre-tournament base in Florida to Swope Soccer Village, where it was due to be in place before the squad begin training after their arrival in Kansas City on Saturday.

"We are investigating a possible theft of equipment from a team vehicle that arrived in Kansas City with items missing this evening," police said.

"The investigation is ongoing. Two subjects of interest were taken into custody pending further investigation."

Balls and boots were among the items believed to have been stolen, according to British media reports.

Reuters has contacted the Football Association for comment.

The theft could affect England's preparations for their World Cup opener against Croatia on Wednesday in Dallas.