Monday's news in 5 minutes.

1. Newborn twins and toddler orphaned after their parents died two weeks apart.

Newborn twins and their two-year-old sister have been orphaned after their mother tragically died on the same day as their father’s funeral.

Florida woman Stephanie Caceres, 27, died on Wednesday, July 26, of an infection reportedly caused by a caesarean section, The Palm Beach Post reports.

Her partner, 26-year-old Jevaughn Suckoo, was to be farewelled by friends and family that day after being fatally shot at their home in a gated West Palm Beach apartment complex on July 11.

No one has yet been charged with the crime.

After the birth of her twins on July 14, a grieving Caceres shared her distress on Facebook.

“I just don’t understand how someone can have the heart to leave three kids without a father especially two that never got the chance to even meet him,” she wrote.

“They didn’t deserve this! I’m trying I really am to stay strong but this has to be the toughest battle I’ve ever had to fight.”

In the wake of Caceres' death, her colleague at Juan E. Batista Pediatrics, Lina Niemczyk, has begun collecting funds donated to the couples' three children.

“Our goal is to secure their future,” Niemczyk told The Palm Beach Post. “It’s a promise to their mom and dad.”

The children are now in the care of their grandparents.

You can donate via GoFundMe. The campaign has so far raised about US$94,000 (AU$118,000).

2. Australian travellers are in for much longer airport check-in times after foiled terror plot.

A two-hour check-in time for domestic travellers in Australia will become the new normal, after authorities in Sydney foiled a suspected terror plot to bring down a plane with a bomb.

Jetstar and Virgin Australia have upgraded their advice from one hour, also telling passengers to limit carry-on and checked baggage to ensure a efficient screening processes, AAP reports.

International travellers should arrive three hours before their fight departure time.

NSW and federal police swooped on five properties in the Sydney suburbs of Surry Hills, Lakemba, Wiley Park and Punchbowl and arrested four men on Saturday afternoon.

They are in custody and will be held there for up to seven days as police comb through the evidence.

The extra check-in time is needed because of "additional scrutiny" and security experts say the arrangements will likely be in place for the foreseeable future.

3. A 24-hour national support line for university sexual assault victims has been launched.

A 24-hour support line for university sexual assault victims is being launched ahead of the release of a national report on campus abuse.

Universities Australia is launching the interim phone line the day before a survey looking into the scale of sexual assault and harassment among students is released by the Australian Human Rights Commission, AAP reports.

"We know the release of the survey is likely to see a greater number of students seeking counselling support," Universities Australia chief executive Belinda Robinson said on Monday.

"We expect the results will be challenging for everyone. But particularly so for students, victims and survivors who have told their stories as part of this important project."

The 1800 572 224 support line will operate from 9am on Monday until November 30 in addition to universities' existing phone and face-to-face counselling services.

All of Australia's 39 universities took part in the AHRC's report being released on Tuesday.

"The results will help us to combat sexual harassment and sexual assault and to improve support for students," Ms Robinson said.

Former commission president Gillian Triggs last year said she hoped the data would shine a light on disturbing initiation rituals, the experience of international students, and the rates of sexual assaults at universities compared to wider communities.

If you need help, you are urged to call the national domestic violence and sexual assault helpline 1800RESPECT (1800 737 732). In an emergency call triple-zero.

4. Police launch National Missing Persons Week as 38,000 people vanish in Australia each year. 

Around 38,000 people are reported missing across Australia each year and on Monday they will become the focus of a national campaign to raise awareness.

Australian Federal Police Commissioner Andrew Colvin and Queensland Police Acting Commissioner Tracy Lord will launch this year's National Missing Persons Week in Brisbane, AAP reports.

The annual campaign was established in response to the disappearance of Perth backpacker Tony Jones in 1982.

Mr Jones, 20, went missing after phoning his family from Townsville on November 3.

This year's campaign will focus on 13 to 17-year-olds, who account for half of all missing persons reported to police and are six times more likely to go missing.

Authorities estimate around 38,000 people are reported missing to police each year.

A 2002 inquest ruled Mr Jones was the victim of foul play, however a new inquest into his disappearance was opened last year, resuming in Townsville this month.

Persons of interest in Mr Jones' disappearance are expected to give evidence.

5. Russia retaliates over sanctions, says it will expel 755 US diplomatic staff.

President Vladimir Putin says Russia will expel 755 US diplomatic staff and may consider imposing additional measures against the United States as a response to new US sanctions, although not for now.

Moscow ordered the United States on Friday to cut hundreds of diplomatic staff and said it would seize two US diplomatic properties after the US House of Representatives and the Senate approved new sanctions on Russia, AAP reports.

Putin said in an interview with Vesti TV released on Sunday that 755 US diplomatic and technical staff would have to leave Russia by September 1.

"Because more than 1000 workers - diplomats and support staff - were working and are still working in Russia, 755 must stop their activity in the Russian Federation," he said.

New US sanctions were in part a response to conclusions by US intelligence agencies that Russia meddled in the 2016 US presidential election, and to further punish Russia for its annexation of Crimea in 2014.

Moscow said on Friday that the United States had until September 1 to reduce its diplomatic staff in Russia to 455 people, matching the number of Russian diplomats left in the United States after Washington expelled 35 Russians in December.

On Friday an official at the US Embassy, who did not wish to be identified, said the Embassy employed around 1100 diplomatic and support staff in Russia, including Russian and US citizens.

Putin said that Russia could take more measures against the United States but not at the moment.

He repeated that the US sanctions were a step to worsening relations between the two countries.

6. 20,000 revellers forced to flee huge fire at music festival Tomorrowland.

A spectacular fire at a music festival in Spain forced the evacuation of over 20,000 concertgoers in Barcelona.

Images showed towering flames consuming a large outdoor stage on Saturday night at the "Tomorrowland" electronic music festival held at Barcelona's Parc de Can Zam.

Barcelona firefighters said there were no serious injuries during the concert evacuation but the event's private security treated 20 people for minor injuries or anxiety, AAP reports.

Firefighters are investigating the cause of the fire.

The "Tomorrowland" website published a statement saying the "stage caught fire due to a technical malfunction."

The festival in Barcelona was one of several offshoot events of a main "Tomorrowland" festival in Belgium.

Organisers say the Barcelona event has been cancelled following the fire.

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