A Teenager With Two Knives Attacked a Gendarme Outside the Israeli Embassy in Belgrade - and the Security Services Say They Were Watching Him

Fifteen minutes past midnight, outside the Israeli embassy in Belgrade. A minor - from Šabac, according to initial reports - shouted "Allahu akbar" and lunged at a member of the Gendarmerie with two knives. The officer killed the attacker in self-defence and suffered a cut to his face.

After the attack, all of Serbia was put on the highest, red level of terrorism alert. That means armed police patrols on the streets, officers in full gear outside shopping centres, railway and bus stations and airports, stepped-up security at diplomatic missions and tighter checks and searches at key points across the country.

Interior Minister Ivica Dačić laid out the details - and in doing so opened a bigger question than he closed. "This is a supporter of the Islamic State. Our service was monitoring him. On his Instagram profile he posted the black flag and symbols of that organisation," Dačić said.

So the services knew. They knew the profile, the boy was under surveillance. And yet a teenager with two knives made it to one of the most heavily guarded addresses in the capital. It's good that the gendarme reacted quickly and that, according to the minister, he is in good condition and expected to be sent home to recover later today. But what does "we were monitoring him" actually mean if the monitoring ends at the embassy entrance?

Dačić and police director General Dragan Vasiljević visited the injured officer in hospital. The investigation into all the circumstances of the attack is ongoing, and police remain on heightened alert.

The Balkans know this scene by heart: red alert, patrols outside shopping centres, a minister in front of the cameras. The hard part comes later, when someone has to explain how a boy the services had their eye on got that far.