Police forces working together on potentially linked hoax bomb calls to schools
Hoax bomb calls have been made to seven primary schools in Northern Ireland, prompting a number of evacuations.
Similar malicious communications were made to schools elsewhere in the UK on Monday and police services are working together to establish if there is a link.
Officers said they have no information to indicate a terrorist link to the incidents.
PSNI Chief Superintendent Garry Eaton said: "Between 9am and 10am the schools, all of which were primary schools, received calls claiming explosive devices had been placed at each location.
"Local police responded immediately, working with the individual school authorities to establish what the circumstances of the calls were and to put appropriate procedures in place to ensure the safety of both pupils and staff.
"Some schools opted to evacuate pupils, in line with their own protocols.
"This was obviously a very serious and worrying situation, particularly for the parents of pupils at the schools, however after thorough police searches of all of the schools, no devices were found."
Commenting on the alerts in Great Britain, Mr Eaton said: "A link is obviously a strong line of enquiry and we will be working closely with our colleagues in the other police services concerned to establish if there is any definite connection between their calls and ours, and we will continue to liaise with them as appropriate as we take our investigation forward."