Russia’s security services late on Sunday night claimed they had uncovered a plot to assassinate President Vladimir Putin during his trip this week to Iran.

Suicide bombers were planning to blow up Mr Putin, Interfax news agency said, citing a source in Russia’s security agencies. Terrorists had been trained to kill the president, the source added.

The Kremlin also confirmed that Putin, who was on his way to Germany to meet chancellor Angela Merkel, had been informed of the alleged plot.

But there were few details. It was not clear why an Iranian terrorist group might target Putin or how Russia’s security agencies learned of the plot on the eve of his visit. “We cannot comment on this information but we confirm that the president has been informed,” a Kremlin spokesman said.

However, Russian President insisted Monday that he would travel to Iran, saying if he paid attention to all the threats against him, “I would never leave home”.

Putin said his trip was planned long in advance and that he would talk with Iranian leaders about their disputed nuclear program, although he stressed the original purpose of the trip was to discuss issues affecting states bordering on the Caspian Sea. During his Iran visit  Putin will meet President Mahmoud Ahmadinejad and attend a summit on Tuesday of Caspian Sea nations. He is the first Kremlin leader to travel to Iran since Josef Stalin attended a 1943 summit with Winston Churchill and Franklin Roosevelt.

His trip follows an acrimonious meeting on Friday in Moscow with the US secretary of state, Condoleezza Rice, and the US defence secretary, Robert Gates. Putin again criticised the Bush administration’s plans to install a missile defence system in central Europe and said Russia was considering pulling out of a cold war treaty banning mid-range nuclear weapons. The two sides also clashed over Iran, with Putin saying he saw no reason for further sanctions against Tehran.

Since Putin became president in 2000, Russian officials have reported two previous plots to kill him on foreign trips. Ukrainian security officials said they foiled an attempt during a summit in Yalta in August 2000. In 2001 Russian security officials said the Azeri security services uncovered a plot to assassinate Putin during a visit to Baku, the capital of Azerbaijan.

Both alleged plots were linked to Chechnya.

Iranian officials have rejected reports about the plot as disinformation spread by adversaries hoping to spoil Russian-Iranian relations.