Iran's supreme leader yesterday urged Lebanon's visiting prime minister, Saad Hariri, to join together with Shiite group Hizbollah to face what he called the real threat facing his country - Israel.
Ayatollah Ali Khamenei said he was pleased that Mr Hariri and the Hizbollah chief Hassan Nasrullah currently had good ties but added that "these relations must be more consolidated", his office's website reported.
"As long as the occupying Zionist regime exists, Lebanon needs resistance," the supreme leader said, referring to Hizbollah's frequent insistence that it - and not Lebanon's national army - is the only genuine deterrent against an Israeli invasion.
The call by Mr Khamenei and the visit to Iran by Mr Hariri come against a background of spiralling tensions in Lebanon over speculation that a special United Nations tribunal prosecuting those responsible for the 2005 assassination of former prime minister Rafiq Hariri, Saad's father, will soon hand down indictments against members of Hizbollah, the Iranian-supported Shiite movement.
Mr Hariri was on the third day of an official visit to Iran. Iran's defence minister, Ahmad Vahidi, assured Mr Hariri on Sunday that Tehran was prepared to come to Lebanon's aid - sentiments echoed earlier by Iran's president, Mahmoud Ahmadinejad, in his meeting with the Lebanese leader.
While extending a hand to Mr Hariri, Iran is also under international pressure of its own over its nuclear programme. According to Mr Ahmadinejad, that pressure came to the streets of the capital yesterday, as one Iranian nuclear scientist was killed and another wounded in what he called "terrorist" attacks.
There was no immediate claim of responsibility, but Mr Ahmadinejad blamed "western governments and the Zionist regime" and vowed that the country's nuclear programme would continue.
Iran's interior minister, Mostafa Mohammad Najjar, and some legislators also blamed Israel
"The operations were of the kind that Israelis are proficient at," Javad Jahangirzadeh, a member of the parliament's national security and foreign policy committee, told the Islamic Republic News Agency (IRNA).
Majid Shahriari, a professor at Tehran's Shahid Beheshti University, was killed and his wife and driver wounded when an explosive attached to his car by men on a motorcycle exploded during morning rush hour, said Hossein Sajedinia, Tehran's chief of police.
Almost simultaneously, Abbasi Davani, also employed at Shahid Beheshti University, was lightly wounded when an explosive attached to his car went off, Mehr News Agency reported. Ali Akbar Salehi, the vice president and head of Iran's Atomic Energy Organization, confirmed that Mr Shahriari had been involved in the country's nuclear programme and had "good co-operation with [the Atomic Energy] Organization".
He warned Iran's enemies "not to play with fire".
"There is a limit to the patience of the Iranian nation. There will be bad consequences if that patience runs out," IRNA quoted Mr Salehi as saying after visiting the wounded physicist in hospital soon after the blast.
Mr Abbasi is a nuclear scientist who was targeted by UN Security Council sanctions against Iran. He has been a member of the Revolutionary Guards since the early days of the Islamic revolution and served as dean for several years of the physics faculty of Imam Hossein University, where the Guard predominates.
According to Mashreq News, the 52-year-old physicist is also in charge of nuclear studies and research at the ministry of defence. Mr Shahriari is not the first Iranian physicist to die violently. In January, Masoud Ali-Mohammadi, another prominent Iranian physicist, was killed when a booby-trapped motorbike exploded near his car as he was leaving home.
Iranian officials blamed Israel and western governments for Mr Ali-Mohammadi's death. Some Iranian legislators and officials say the killings are aimed at deterring the scientists from working for the country's nuclear programme.
International concern over the programme has led to pressure for US military action from both Israel and some Arab governments, as some of the thousands of secret US government documents released yesterday by the online whistleblower WikiLeaks suggest.
Mr Jahangirzadeh suggested yesterday that military actions were already taking place. "Continuation of these crimes against our nuclear scientists shows that they mean to make our scientists regret taking the road that they have. They are trying to create an atmosphere of terror to prevent our scientists from moving ahead," he said. Iran consistently has insisted that its nuclear programme is only for peaceful purposes.