Courier services have told customers that the Venezuelan customs authority has banned them from importing items such as gas masks, slingshots and bulletproof vests used by some demonstrators in anti-government protests.

Other prohibited items include first aid supplies such as burn cream and gauze, according to emailed messages sent to clients this week by the package delivery companies. These goods have been used to treat injured protesters.

Courier services sending the advisories included local service Zoom and the Venezuela office of Mail Boxes Etc., known as MBE.

Another company, BVA Export, told clients in an email, "It is not allowed to send gas masks and items that can be used for defence and/or attack in the Venezuelan protests.” It included a detailed list of the products that it said had been banned.

There was no immediate response by the companies to requests for comment.

Government officials have publicly accused the opposition of using courier services to equip demonstrators in nearly two months of near-daily clashes with security forces.

Agencies