The Zagreb-London flight, scheduled for 8.35 am, was rescheduled for 7.56 pm.
A new security regime was introduced this morning and all passengers travelling to Great Britain and the United States must travel without hand baggage.
The only items that can be taken into the plane are wallets with money and credit cards, sunglasses without cases, ID cards, travel documents, flight tickets, necessary medicines (not in liquid condition), baby food sufficient for the duration of the flight and child toiletries, women's toiletries, keys (not electronic ones) and handkerchiefs.
The allowed items must not be carried in pockets, but in a transparent plastic bag, Matkovic said.
The special security measures will remain in force until further notice.
According to the latest reports, three London airports will be closed until 6 pm today.
There are no problems on other flights and they are proceeding according to schedule, Matkovic said, adding that he expected all planes to fly according to their regular schedule on Friday.