MANCHESTER, N.H. (AP) – A Northwest Airlines plane landed Friday night at Manchester-Boston Regional Airport with a tour group of about 15 passengers saying they felt sick, an airport spokesman said.

J. Brian O’Neill, airport spokesman, said the passengers were part of a tour group that was returning from Branson, Mo.

The group started to feel ill before boarding Flight 1220 in Detroit, bound for Manchester, O’Neill said. The flight landed at 11:15 p.m.

It’s not clear what made the passengers feel ill or what they had complained of. Emergency personnel evaluated those passengers and released them; they were not hospitalized, O’Neill said.