Images broadcast Sunday included warplanes dropping bombs on targets in the desert, rockets being launched and paratroopers boarding Chinook troop helicopters. Iranian leaders had earlier warned that any attempt by Israel to destroy Iranian nuclear facilities would be met with a military response. "If the enemy tries its luck and fires a missile into Iran, our ballistic missiles would zero in on Tel Aviv before the dust settles on the attack," said Mojtaba Zolnour, Supreme Leader Ayatollah Ali Khamenei's representative in the Revolutionary Guard Corps, told the government-run Islamic Republic News Agency (IRNA) on Saturday.

The display of military muscle Sunday came as Iran's envoy to the International Atomic Energy Agency, Ali Asghar Soltanieh, insisted Iran needs guarantees it will receive nuclear fuel on time for its research reactor if it is to agree to a swap of uranium proposed by the West, reported semi-official Iranian Students' News Agency (ISNA).

The United States, Russia and France have said they are running out of patience with Iran, which has not given a formal answer on a proposal for trading a large part of Iran's stockpile of low-enriched uranium for the higher-enriched uranium that the country needs for medical uses, such as cancer treatments.

"The main issue is how to get a guarantee for the timely supply of fuel which Iran needs," Soltanieh said. "We are ready to have negotiations with a positive approach, but because of a lack of confidence with the West, we need to have those guarantees."

Previous statements by Iranian leaders have suggested that the nation was unlikely to agree to a deal.

As President Mahmoud Ahmadinejad on Sunday started a five-day trip to Africa and South America, a former vice president was sentenced to six years in prison in connection with protests over June's presidential election. Mohammad Ali Abtahi, a cleric and prominent blogger within Iran's reformist movement, was temporality released on $700,000 bail, the state news agency IRNA quoted Tehran prosecutor Abbas Jafari Dowlatabadi as saying on Sunday.

Abtahi, a strong critic of Ahmadinejad's government, made televised confessions after his arrest in June. He also updated his popular blog from prison. In one posting while being held in state custody, he called his interrogator "his friend" and he repudiated his involvement in the protest movement following the election, which officially ended in an Ahmadinejad landslide but which the opposition claims was rigged.

Abtahi's wife, Fahimeh Mousavinejad, said in an interview on Sunday that her husband has told her that parts of his confessions were made under duress. She was still waiting for him to be brought home from prison. "They have placed fear in our hearts, I can only hope he will really come home today," she said.