Several people were arrested in Copenhagen early on Tuesday for allegedly planning a terrorist act, stated a statement released by Denmark's Security Intelligence Service PET.

According to PET, the arrests were made after prolonged surveillance of the persons concerned.

However, no details were available about how many people were arrested, their nationalities or which city the culprits were targeting.

PET is scheduled to hold a news conference later to give more information about the issue.

The recent months have witnessed a series of arrests by the PET under the anti-terrorism legislation passed after the 9/11 attacks.

In February, a Danish Muslim youth was sentenced to seven years in prison for planning an attack in Europe. A Moroccan-born Dane was sentenced to three years in prison on charges of inciting Muslims to wage a holy war in April.

Trial is yet to start for four Muslim men, accused of plotting a bomb attack in Denmark.