President Putin has thanked Donald Trump for the US's help in foiling a plot to attack the city of Saint Petersburg.

The White House has confirmed that the Russian president called his US counterpart on Sunday after the CIA supplied intelligence which allowed Russia's security services (FSB) to break up a "terror cell" planning an attack on Russia's second biggest city.

"The information received by the CIA was enough to detect, hunt down and arrest the criminals," the Kremlin said.

Seven members of an Islamic State group cell have been arrested by the FSB, Russian officials added, after they were allegedly planning a suicide bombing in crowded areas of the city.

Police confiscated a large number of explosives used to make homemade bombs, automatic rifles, munitions and extremist literature, the Kremlin said.


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President Putin also pledged to pass on any information received about threats to the United States and its citizens from terrorists to the CIA.

This is the second time in less than a week that two of the world's most powerful leaders have exchanged messages of praise.

Mr Trump said on Friday he had called Mr Putin to thank him for comments he made about the US President's efforts to grow the American economy.

"He said very nice things about what I have done for this country in terms of the economy, but he said also some negative things in terms of what is going on elsewhere," Mr Trump said.

"The primary point was to talk about North Korea. We would love to have his help on North Korea."

Mr Putin has said he and President Trump are on first name terms, which is "how relations should be between people like us".

Russia has been on high alert ahead of the World Cup and the presidential election next year.

FSB chief Alexander Bortnikov said on Tuesday the country was monitoring the possible return of jihadists from Syria, a threat which has increased since Moscow's military intervention in the country.

Russia has suffered several attacks this year, including a bombing on the Saint Petersburg metro in April that left 14 people dead.