11.   Longstanding tensions in Tibet ratchet up every March around a series of anniversaries.

12.   Longstanding ethnic tensions in the Niger River delta region has been exacerbated by the influx of oil firms.

13.   The anniversary arouses profoundly different feelings among Chinese and Tibetans and always quickens longstanding tensions inside Tibet.

14.   The Express quoted witnesses as saying clashes between laborers and guards are commonplace, the riot was believed to be an outburst of longstanding tensions.

15.   The traditional rivals began efforts last year to ease longstanding tension.

16.   There has been longstanding tension between hotels and religious authorities over celebrations of the Christian New Year.

17.   Longstanding racial tensions and complaints of persistent police harassment of young people underlay the incidents.