Direct flights between Ukraine and Russia will stop tomorrow, as new sanctions initiated by Kiev come into effect.

Moscow first called Kiev's ban on Russian airlines "madness", then announced that it would mirror the move. Ukraine now says flights will end at midnight tonight after last-minute crisis talks failed. Up to 70,000 passengers a month will be affected.

The sanctions are intended to punish Russia for annexing Crimea and supporting armed rebels in eastern Ukraine. The fact that they have been introduced now, when a ceasefire is finally holding on the ground, shows how bitter relations remain.

Russia has accused Ukraine of shooting itself in the foot with the move, pointing out that most passengers are Ukrainian travelling to work in Russia, visiting relatives or in transit.

But two-thirds of all passengers travel on Russian airlines. Russia's transport minister has estimated that the loss in ticket sales to both countries will run to around $110m a year.

The ban is already angering passengers from both countries.

Last-minute talks to find a compromise are under way - so far to no avail - and the chances of success look slim in this climate.

From tomorrow, passengers will be forced to take longer, more expensive routes via third countries, or to brace themselves for a 13-hour trip by train.