NNEKA CHILE WHEN Divine Umukoro refused to pay police a bribe after breaking Lagos state's night-time curfew, she says they slapped her, slashed her car tyres and threatened violence. A video of the incident went viral on Nigerian blogging sites, and Citizens' Gavel, a non-profit organisation that fights against police misconduct, stepped in, helping her to recover her seized car within three days. The police have declined to comment on the incident. "When the whole thing started with the hitting, with the slapping of my face, pushing my friend - I felt so angry," Umukoro, 25, said of the July…