Iran's unprecedented strikes on a US base in Qatar were carefully calculated to provide an exit from hostilities with Washington and set up a truce with Israel, according to analysts and an official.

Monday's missile launches were signalled well in advance, minimising the risk of injury and giving every opportunity to shoot down the projectiles -- resulting in a fireworks display of booms and flashes above Doha.

Gaza's civil defence agency said Israeli forces killed another 46 people waiting for aid in the Palestinian territory on Tuesday as rights groups and UN agencies slammed the US-backed food distribution system.

Civil defence spokesman Mahmud Bassal told AFP that 21 people were killed and around 150 wounded by Israeli fire near an aid point in central Gaza early Tuesday, and that another 25 were killed in a separate incident in south Gaza.

Tehran was far from its usual hustle and bustle on Tuesday, but life was regaining some colour despite concerns from residents that a tentative ceasefire between Iran and Israel may not hold, after nearly two weeks of war.

In Tajrish bazaar in north Tehran, everyone had their own opinion on whether the end to the fighting announced by US President Donald Trump would last.

Alarm has intensified over the welfare of inmates after an Israeli strike on Evin prison in Tehran, one of Iran's most notorious penal complexes which haunts prisoners long after they are released.

Rights groups say that Evin, which is believed to have the capacity for hundreds of inmates, is home to dozens of "political prisoners" innocent of any crime, including foreigners, and women who are kept in a separate wing.

A little-known Sunni Muslim extremist group claimed responsibility on Tuesday for a weekend suicide attack against a church in Damascus, while the Syrian government insisted they were part of the Islamic State group.

Sunday's attack killed 25 people and wounded dozens, striking terror into Syria's Christian community and other minorities.

A statement from Saraya Ansar al-Sunna said an operative "blew up the Saint Elias church in the Dwelaa neighbourhood of Damascus", adding that it came after an unspecified "provocation".

The United Nations on Tuesday condemned what it said was Israel's "weaponisation of food" in Gaza and called it a war crime, urging its military to "stop shooting at people trying to get food".

The head of the UN agency supporting Palestinian refugees also called a new US- and Israel-backed food-distribution system in the Gaza Strip an "abomination".

The Gaza Humanitarian Foundation began handing out food in Gaza on May 26 after Israel completely cut off supplies into the occupied Palestinian territory for more than two months, sparking warnings of mass famine.

Classified US intelligence suggests that American strikes on Iran set back its nuclear programme by just a few months, contradicting President Donald Trump's claim of total destruction.

Here are the latest developments as a truce between Iran and Israel appeared to be holding early Wednesday:

- US intel report -

US media on Tuesday reported that a classified US intelligence document had concluded that American strikes last weekend did not fully eliminate Iran's centrifuges or stockpile of enriched uranium.

As night falls in Israel's coastal city of Tel Aviv, hundreds make the familiar descent into the depths of the metro to escape the latest salvo of Iranian missiles.

For those with no safe shelters near their homes, the city's underground stations and car parks have become vital refuges since the war began on June 13.

Despite nightly missile barrages, Israel's casualty toll has remained relatively low, with authorities repeatedly stressing the importance of taking cover in life-saving protected spaces.

Mahmoud Khalil, one of the most prominent leaders of pro-Palestinian protests on US campuses, recounted his experience surviving 104 days in Immigration and Customs Enforcement detention after being targeted for deportation by the Trump administration.

"I shared a dorm with over 70 men, absolutely no privacy, lights on all the time," the 30-year-old said Sunday on the steps of Columbia University, where he was a graduate student.

Iran said on Tuesday that it was ready to return to negotiations with the United States, as a fragile ceasefire in its war with Israel took hold after 12 days of strikes that pummelled the Islamic republic's nuclear facilities.

But even as he appeared to express willingness to revisit nuclear talks derailed by Israel's surprise attack, Iranian President Masoud Pezeshkian said his country would continue to "assert its legitimate rights" to the peaceful use of atomic power.

The United States on Sunday had joined Israel's campaign with strikes on key nuclear sites.