Information provided by the CIA helped Russian security services foil an attack on St Petersburg's Kazan cathedral, BBC reports quoting the Kremlin. The attack was allegedly planned to take place on Saturday, officials say. In a phone call, President Vladimir Putin thanked Donald Trump for the CIA's intervention, the Kremlin said. Putin told Trump that Russia's special services would hand over information on terror threats to their US counterparts, it added.

Russia's FSB security service said in a statement on Friday that it had detained seven members of a cell of Islamic State supporters and seized a significant amount of explosives, weapons and extremist literature. The cell was planning to carry out a suicide attack at a religious institution and kill citizens on Saturday, the FSB statement said (in Russian).

The group was preparing explosions targeting the cathedral and other public places in Russia's second city, the Kremlin statement said.

It added that Putin had asked the US president to pass on his thanks to the CIA director and the operatives involved.

White House press secretary Sarah Sanders confirmed that Trump and his Russian counterpart had spoken on Sunday.

An explosion on St Petersburg's metro system in April, which killed at least 13 people, is thought to be linked to jihadists.

Returning militants from Syria pose a real threat to Russia, the head of the FSB was quoted as saying on Tuesday.