From: BBC by Adam Easton,Warsaw correspondent and Jaroslav Lukiv

Two Ukrainian citizens who long worked for Russian intelligence have been identified as the suspects behind two acts of sabotage on Poland’s rail network, Polish Prime Minister Donald Tusk said.
One suspect had already been convicted in absentia of acts of sabotage in Ukraine, Tusk told parliament.
On Monday, he visited the scene of an explosion near Mika, south-east of Warsaw, which damaged the railway line leading to the Ukrainian border at the weekend, and called it an “unprecedented act of sabotage”.
Another incident down the line near Pulawy on Monday forced a packed train to stop suddenly and damage was found to overhead cables.
The Kremlin brushed off suggestions of Russian involvement.
Russian President Vladimir Putin’s spokesman, Dmitry Peskov, said: “It would have been really strange, if Russia hadn’t been blamed first.”
“Russia is accused of all acts of hybrid and direct war… in Poland,” he told Russia’s state-run media, adding: “Russophobia is certainly rampant there.”
Polish authorities had initially said there was a very high chance that the two acts of sabotage on the Warsaw-Lublin railway line had been ordered by a “foreign service”.
Then a spokesman for Poland’s special services minister said on Tuesday that “everything points to them being Russian special services”.
“The goal was to cause a rail catastrophe,” Tusk told MPs.
The Polish prime minister said he would not disclose the names of the two suspects as this could complicate the operation, though he told parliament that one was living in Belarus and the other was a resident of eastern Ukraine.