|US denies role in Iran murder|
The US has dismissed an accusation by Iran that it was behind the murder of an Iranian nuclear physics professor, who was killed in a bomb blast.
Mark Toner, a US state department spokesman, on Tuesday called the allegation "absurd", hours after Massoud Mohammadi, a professor at Tehran University, was killed in the north of Tehran, the capital.
Iranian media reported that a bomb strapped to a motorcycle was triggered by remote control outside Mohammadi's home, killing him.
Iran's foreign ministry had said that US and Israeli "mercenaries" were behind the attack.
Earlier, the Iranian state-run Press TV reported: "The explosion took place near the professor's home in Qeytariyeh neighbourhood, in northern Tehran".
It said Mohammadi was a "staunch supporter" of Iran's 1979 revolution and that he was "assassinated in a terrorist act by counter-revolutionary elements".
The broadcaster said police and security officials have launched an investigation.
Iranian media reports described Mohammadi as a nuclear energy professor, citing Abbas Jafari Dolatabadi, the Tehran prosecutor.
"Massoud Ali-Mohammadi was a professor in the nuclear field and there has so far been no arrests of those behind this incident," the Fars News Agency reported.
Al Jazeera's Alireza Ronaghi, reporting from Tehran, said Mohammadi might have had links to Iran's disputed nuclear programme.
"Authorities who decided to remain unnamed tell me that Mohammadi had some connections with Iran's nuclear programme and this [the murder] could be related," he said.
He said it was unclear who might have been behind the bombing.
"Anyone who is connected to Iran's nuclear programme could be an easy target for [foreign] intelligence services.
Baqer Moin, an Iranian author and journalist in London, said Iranian media have accused "Zionist agents" as being behind the blast.
"They are looking towards people who are interested in delaying the Iranian nuclear programme. Websites close to the [Iranian] authorities are making these statements," he told Al Jazeera.
"There have been in the past reports that many nuclear scientists or people who wanted to join the Iranian nuclear organisation have been intimidated.
"There also were claims of other assassinations. But this is the first time in recent months that in Tehran such an occurrence has happened."
They demand that Iran accept a UN brokered offer that would delay Iran's ability to make a nuclear weapon as well as engage in broader talks with the ultimate goal of persuading it to stop its enrichment programme.
The White House also reacted to the remarks.