I crossed mauritania a few days ago.
There are a huge number of police on the roads- check points galore so have heaps of 'fiches'
Also army guys have been pulled in to patrol - you recognise them as they have new uniforms.
Hassle endlessly for money 'cadeaux' - whatever you do, don't pay as it sets a really bad precedent. They all ask, some more bullish than others.
Kiffa was a very uncomfortable passage- one policeman took our 3 passports, commandered an vehicle and drove off- I had to stick to him like glue- Not a good time was had in a military building with some 'official' in a djellaba and a cheich covering virtually his whole face fiddled endlessly with passports- despite requests, no information or identifcation was given aside from 'new procedure'.
Then another mad dash accross town to the 'director's ' house- a private abode where the said 'director' was in bed!
... WTF?? passports were held there and eventually written into and signed and stamped -very tense moments were experienced and most officials were quite bullish- verging on agressive.
Money requests 'pour aider le passage' were constant.
We were glad to see the minefield crossing again
remain calm, be polite but be assertive and stand your ground- they smell 'weak' people a mile off...and opportunity then knocks...