TEHRAN, Iran, June 18, (AP):  Explosions were heard in Iran's capital as Israeli warplanes pounded Tehran overnight and into Wednesday. Less than a week into the conflict, Israel says its aircraft have free rein over the city’s skies.

Iran launched a small barrage of missiles at Israel with no reports of casualties, and Israel has eased some restrictions for civilians.

Meanwhile, fear has gripped the Iranian capital as the streets are empty, businesses closed, and communications patchy at best. Thousands have fled.

Iran’s supreme leader on Wednesday rejected U.S. calls for surrender and warned that any military involvement by the Americans would cause "irreparable damage” to them.

U.S. President Donald Trump initially distanced himself from Israel’s surprise attack on Friday that triggered the conflict, but in recent days has hinted at greater American involvement, saying he wants something "much bigger” than a ceasefire.

The U.S. has also sent more military aircraft and warships to the region.

Late Wednesday afternoon, internet access across Iran crashed. Authorities offered no immediate explanation. Just after 4 p.m. local time, a likely Israeli airstrike sent a giant plume of gray smoke skyward in the eastern reaches of Tehran.

It wasn’t immediately clear what was targeted. Israel is easing some restrictions for civilians that have frozen the country in place over the past week, the military announced on Wednesday, six days into the confrontation with Iran. While schools are still closed, people will begin returning to workplaces where there is access to shelters.

Restrictions are being eased further in areas along Israel’s periphery, which have been targeted fewer times than the country’s center. "This decision to gradually open the economy in the various regions is a message of victory over the Iranian enemy,” Israeli Defense Minister Israel Katz said on Wednesday.

Iran has fired fewer missiles as the conflict has worn on, allowing Israeli air defense systems greater accuracy with interceptions.

State television has aired footage of Iran’s Supreme Leader Ayatollah Ali Khamenei giving a statement that was read out by a TV anchor a short while ago.

The footage strikingly contrasted against the high-quality recording typically produced of his speeches, with his voice echoing as he sat in a room with beige curtains behind him.

A portrait of Grand Ayatollah Ruhollah Khomeini, who Khamenei succeeded, was over his left shoulder, with an Iranian flag to his right. Khamenei warned the United States that joining the Israeli strikes targeting the Islamic Republic will "result in irreparable damage for them.”

Germany’s foreign minister has underlined European countries’ willingness to talk to Iran about a solution to the crisis over its nuclear program. But he says there needs to be movement from Tehran.

Johann Wadephul said Wednesday that "it is never too late to come to the negotiating table, if you come with honest intentions.”

He spoke two days after he held a call with Iranian Foreign Minister Abbas Araghchi along with his French and British counterparts and the European Union foreign policy chief.

Wadephul said the European officials made clear that their countries -- which were part of Iran’s 2015 nuclear agreement with world powers -- "still stand ready to negotiate on a solution.” But he added that "Iran must now move urgently. Iran must take confidence-building and verifiable measures,” including a credible statement that Tehran is not striving for a nuclear weapon.

The European Union has helped evacuated about 400 its citizens out of Israel via Jordan and Egypt as part of its efforts to coordinate emergency response to the conflict within the 27 nations of the bloc. "Up till now, we have an estimate that over 400 EU citizens were repatriated via this civil protection mechanism of the EU,” said Eva Hrncirova in Brussels on Wednesday.

She said the EU was fielding requests by Slovakia, Lithuania, Greece, and Poland for assistance in evacuating from the Middle East. "Member states coordinate the list and we co-finance these flights up to the 75% of the transport costs,” she said. Iran’s supreme leader has warned the United States that joining the Israeli strikes targeting the Islamic Republic will "result in irreparable damage for them.”