Mass tourism is given a new meaning by watching an organised Russian tour group on a Bulgarian beach. In fact, in that sentence, "organised" may be redundant. Or, "regimented" may be more appropriate.

We have just returned from two weeks at a resort near Varna where there was ample opportunity, however unsolicited and not necessarily welcome, to observe a succession of large groups of bussed-in young Russians operating according to modes of behaviour that appeared to have been drawn from a dusted-off copy of the Komsomol equivalent of Scouting for Boys.

Marshalled by group leaders using whistles and a megaphone, the Russian teenagers – a later group was made up of students – advanced en masse into the water. A subsequent blast on the whistle, and with grim determination they strode through the shallows on to the sand. Mused a Bulgarian friend, watching with me, "it looks like the D-Day Landings".

It may be understandable that the organisers wanted to lose no one in the waters, hence the rigid control, but other incidents were less acceptable.

At one point, two Bulgarian lifeguards were dispatched to ask our group – all Bulgarians bar me – to move further away down the beach. The Russians were complaining that they were being intruded on by Bulgarians and British tourists (a reference to me, in a case of mistaken identity) and did not want to mix with anyone but Russians. "Then they should have stayed in f…ing Russia," responded one of our number.

Another episode was when a phalanx of buses was disgorging the newest arrivals at their hotel. Police were brought from Varna to block the road to allow the operation to proceed. When one of us protested: "I am a Bulgarian, I pay my taxes and this is my road," the police officer responded, with some grace, that he quite agreed – especially because there was an adequate parking area behind the hotel and so no need to obstruct the road.

The sight which quite defied belief was one that we watched from a local restaurant. At the appointed hour, the regiment descended on the beach, and having been addressed by megaphone (on what theme none of us could make out, even those who understood Russian, because the distance was a tad too far), were marched in a semi-circular route around the beach. Until you have seen swimming-costume-clad Russian students marched around a beach, you have not seen everything.

Already we had objected to the violation of Bulgarian law that preserves beaches as public spaces; given that we were witnessing a military exercise on Nato soil, I wanted to summon the gunboats.

Bulgarian serving staff complained vocably to us about the Russians’ rudeness (a role reversal if ever there was one, waitstaff complaining about arrogant behaviour by foreign customers, but I could see their point).

Sting sang, "I hope the Russians love their children too"; no doubt, but I would never want mine marching on anyone’s beach, and behaving not as tourists, but an occupying power.