The foreign ministry in Pristina said the latest arrest happened on Friday, when Serbian police detained Kosovo citizen Hilmi Kelmendi as he was travelling to Germany.
Kosovo urges citizens to avoid Serbia after 'unacceptable' arrest (Sky News)
The arrest of a 36-year-old man accused of committing war crimes comes after a police director was detained over "terrorism".
People in Kosovo have been warned to avoid travelling through neighbouring Serbia following the "unacceptable" arrest of a Kosovo Albanian - the second in a month.