COPENHAGEN (Reuters) - Danish police detained a man on Monday suspected of a spate of bomb hoaxes that forced the evacuation of two provincial airports and two shopping malls earlier in the day.

The suspect was being held in Slagelse, a town about 100 km (60 miles) west of Copenhagen, police said in a statement.

"The man is suspected of sending a number of threats to Danish airports, shopping centers and hospitals," it said, without saying how he sent the hoaxes. It did not name the man nor suggest a motive.

Domestic airports at Roskilde and Aarhus and a shopping mall at Roskilde, about 35 km (22 miles) west of the capital, reopened after searches by dogs trained to detect explosives, police said.

A second shopping center in Slagelse was still being checked in the early evening.

"It wasn't chaotic or hectic, but there was this feeling of apprehension," Anton Bestle, an eyewitness who was evacuated from RO's Torv shopping center in Roskilde, told Reuters.

Additional threats were sent to other locations in the capital area, including Copenhagen Airport, but were deemed hoaxes from the start, partly because they were all from the same sender, the police told Danish broadcaster TV2.

(Reporting by Nikolaj Skydsgaard and Alister Doyle; Editing by Mark Trevelyan and Hugh Lawson)