Many international train passengers required to wear masks from Monday

Train passengers traveling from the Netherlands through Belgium will be required to wear face masks during their journeys beginning on Monday. Dutch rail service NS, and international train operators Eurostar and Thalys all issued warnings about the new rule change over the weekend.

Starting on May 4, all passengers on the Thalys headed to Belgium or France must have a mask in order to board the train. Homemade masks, medical masks, and respirators would all be acceptable and in keeping with guidelines provided by the Belgian authorities, the Thalys said.

Eurostar strongly recommended people carry a mask with them when they travel. "If you don’t have a mask you may be refused travel on our services. We’d like to advise you that fines may be imposed in France and Belgium if you’re not wearing a mask," Eurostar said.

"Any type of mask is suitable as long as it effectively covers your nose and mouth," Eurostar added. The NS also said passengers on international trains could use a cloth, scarf or shirt.

The NS also recommended that people traveling to Germany wear mouth and nose protection, noting that different German states have different rules, but their is an obligation to cover the mouth and nose when using many forms of public transit there. From May 11, a mask or scarf covering both the nose and mouth will also be required when using public transit in France, the NS and Thalys said.