persecution. See Rife v. Ashcroft, 374 F.3d 606, 612 (8th Cir.2004). Being forced on occasion to work without pay for the police is troublesome, but we cannot conclude that this alone rises to the level of persecution. “[P]ersecution is an extreme concept” and low-level types of intimidation or harassment are not sufficiently severe. Shoaira, 377 F.3d at 844 (internal marks omitted). We have stated that brief periods of detention, ethnic conflict, or isolated violence do not necessarily constitute persecution. See Ngure v. Ashcroft, 367 F.3d 975, 990 (8th Cir.2004) (noting isolated violence does not compel a finding of persecution); Al Tawm v. Ashcroft, 363 F.3d 740, 743 (8th Cir.2004) (noting brief detention not necessarily persecution); Feleke v. INS, 118 F.3d 594, 598 (8th Cir.1997) (<HOLDING>).' We conclude that substantial evidence
holding political unrest and ethnic conflict do not compel a finding of persecution holding that a minor beating even in conjunction with threats did not compel a finding of persecution holding that evidence of multiple interrogations and 24hour detention did not compel finding of persecution holding that evidence of kidnapping at gunpoint interrogation and beating did not compel finding of persecution holding that minor abuse during brief detention did not compel finding of past persecution