"An incident at Radyr Comprehensive School earlier today has concluded. The school was evacuated as a precaution following a malicious communication received by the school. No objects of concern were located, no-one was harmed and enquiries are on-going", the police said in a statement.
Earlier on Friday, children were sent home as the school’s headteacher apologised for the inconvenience and promised to give them further details later.
Later on, the WalesOnline news outlet quoted a spokeswoman for the Radyr Comprehensive School and the Cardiff council as saying that the school had received a malicious communication.
Under UK law, malicious communication refers to any indecent, grossly offensive or threatening message sent with the purpose of causing distress or anxiety, and the offender could be sentenced to up to two years in jail or a fine or both.