Tensions have been rising at the Venezuelan border with Colombia amid president Nicolás Maduro's ban on aid entering the country. Our correspondent Harriet Alexander sent this video report from the front line of the clashes.

Never before has so little been known, by so many, about so few.

Sure, we knew that Saturday, February 23 - #23F in the parlance of Juan Guaido’s 1.4 million Twitter followers – was the day of the “avalanche of aid”. Mr Guaido, the self-declared “interim president”, trumpeted the day for weeks as the moment when Venezuela’s long-suffering people would get the aid they so desperately needed.

And sure, we knew what the aid would consist of: the US had flown in hundreds of tonnes of supplies, as had Chile and Colombia. But the whole day was, to steal a phrase, a riddle wrapped in an enigma.

We had no idea how it would pan out. Nicolas Maduro, Mr Guaido’s rival for the presidency, vowed to block the aid – but would he really use force, with the whole world watching?

Everyone had a theory. But no one would dare to call it either way. And in the end, both sides emerged gravely wounded.