Those who, acting as a group, invade or occupy, against the will of its owner, the domicile of a public or private legal entity, an office, establishment or premises, even if it is open to the public, and thereby cause a relevant disturbance of public peace and its normal activity, shall be punished with a prison sentence of three to six months or a fine of six to twelve months, unless the acts are already punished with a more serious penalty in another provision of this Code.