Russia's security services (FSB) said on Wednesday that they had arrested eight people suspected of involvement in the organisation of Saturday's bomb attack on the bridge linking Crimea to Russia.
In a statement, the FSB said five Russians and "three Ukrainian and Armenian citizens" had been arrested.
"The explosive device was concealed in 22 pallets of plastic film rolls weighing a total of 22,770 kilos," the FSB said.
The security agency says the explosives were sent in early August by ship from the port of Odessa in Ukraine to the port of Rousse in Bulgaria. They then passed through the port of Poti in Georgia and were shipped to Armenia before arriving by road in Russia.
The Russian services claim that the explosive device entered Russia on 4 October in a truck registered in Georgia, before reaching the Russian region of Krasnodar, which borders Crimea, on 6 October, two days before the explosion.
The FSB claims that this "terrorist attack" was organised by Ukrainian military intelligence, saying that an agent in Kyiv had coordinated the transit of the explosives and had been in contact with the various intermediaries.
Other experts have speculated that the explosion came from below the bridge, and was not caused by a truck bomb on the bridge itself.
In response to the attack on the bridge, Russia carried out massive bombing raids across Ukraine on Monday and Tuesday.
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