President Vladimir Putin will go ahead with a planned visit to Tehran, Iran's Foreign Ministry said, despite a Russian news agency report that a plot was being prepared to assassinate him there.

"Mr Putin will ... be arriving this evening," Iranian Foreign Ministry spokesman Mohammad Ali Hosseini said.

Russia's Interfax news agency reported earlier, citing unnamed sources, that Putin had been warned by his special services of a possible plot to assassinate him during a visit to Tehran this week.

The Kremlin said Putin had been briefed on the reports but the Russian leader, now visiting Germany, has not yet commented himself. Russian state television channels repeated the reports today.

Kremlin deputy spokesman Dmitry Peskov, in Tehran ahead of Putin's scheduled arrival, said this morning:

"According to the schedule, the President (Putin) is coming tonight. We have no information that he is changing his plans."

Putin, arriving in Germany last night for talks likely to cover tensions over Iran's nuclear programme, waved a hand dismissively when asked about the plot report and told reporters "later".

The President was due to meet Chancellor Angela Merkel this morning and hold a news conference.

Iran dismissed as baseless the Interfax report that suicide bombers were preparing an attack on the President. It described the allegation as "psychological warfare" calculated by Tehran's enemies -- an apparent reference to Western powers -- to undermine Russian-Iranian relations.

Interfax reported earlier that security services had been told suicide bombers and kidnappers were training to kill or capture Putin on his visit, due to start tomorrow. It did not say who might be behind such groups in the Islamic Republic.

The trip to Tehran will be watched closely by Western capitals pushing Moscow for a harder line reining in an Iranian nuclear program they fear masks a drive for an atomic bomb. Iran denies nuclear arms ambitions and is building a nuclear reactor with Russian help.

"A reliable source in one of the Russian special services, has received information from several sources outside Russia, that during the president of Russia's visit to Tehran an assassination attempt is being plotted," Interfax said.

"A number of groups of suicide bombers are preparing for this aim," Interfax, one of a small circle of Russian agencies with special access to the Kremlin, added.

It gave no details of who the sources were or whether they were linked in any way to Western governments; nor was it clear why the Kremlin would make such a report public in this way just before the planned visit.

"I think this is very serious information," the head of the Russian parliament's security committee, Vladimir Vasiliev told the Vesti television news channel. "I hope that through the cooperation of international special services all this information will be verified and the necessary steps taken."

The semi-official Iranian news agency quoted an "informed source" as saying Putin was still expected in Tehran.

"Western politicians and their media were trying to persuade Putin in a political action not to travel to Iran and now that they have failed in that, they intend to convince him not to travel to Iran by...rumor of an assassination."

Putin, who will be the first Kremlin chief to visit Iran since Josef Stalin went in 1943, is set to take part in a summit of Caspian Sea states.

But a meeting planned with Iranian President Mahmoud Ahmadinejad could give him a chance to seek a peaceful compromise over Tehran's nuclear program and to demonstrate his independence from Washington on Middle East issues.

Russia says engaging Tehran is a more effective way of tackling Iran's nuclear program than isolating it. It sells weapons to Iran, in defiance of U.S. concerns, and is building a nuclear power station for Iran at Bush