Putin said Ukraine had prepared a “window” for the attackers to cross the border – currently a war zone.

Ukraine has vehemently denied involvement but two of Putin’s most powerful allies, Security Council chairman Nikolai Patrushev and FSB state security service head Alexander Bortnikov, on Tuesday both directly blamed Kyiv for the attack, albeit without producing any evidence.

However, Lukashenko, a close ally of Putin, told journalists that Belarusian and Russian security services had coordinated their actions as the suspects’ car fled southwest from Moscow to the Bryansk region, bordering both Ukraine and Belarus, where it was apprehended.

He said Belarus had quickly set up checkpoints at the border.

“That’s why they couldn’t enter Belarus. They saw that, so they turned away and went to the area of the Ukrainian-Russian border,” he was quoted as saying by the state news agency BelTA.

“Putin and I didn’t sleep for a day,” he added. “… There was constant interaction.”Bortnikov said Russia knew that Ukraine had been training Islamist militants in the Middle East.

US officials have said the US has intelligence confirming Islamic State’s claim of responsibility for the attack. Putin himself has acknowledged that Islamist militants carried it out, but says he wants to know who ordered it.