"Two people were missing."
Translation:Det manglet to personer.
"Det manglet to folk" literally means "Two peoples were missing", as in for instance the Mayans and the Inuit, or perhaps Norwegians and Germans. ("Da det internasjonale rådet ble satt sammen, manglet det to folk/folkeslag: nordmennene og tyskerne.") Although I think people would understand what you were trying to say.