Thefts of oxygen mounted as Mexico reported its highest daily death toll since the coronavirus pandemic began, with 1,584 deaths confirmed.
There was also a near-record one-day rise in new virus cases of 18,894.
The Mexican Social Security Institute reported that an armed man burst into a government hospital in northern Sonora state around noon on Tuesday and stole seven oxygen tanks.
The institute said the man pointed a gun at a hospital employee, demanded to know where the oxygen was kept, and took four empty canisters and three full ones.
Authorities in the city of Navajoa are looking for the man and and another suspect who drove off in a car carrying the tanks.
Also on Tuesday, police in the town of Tultepec, just north of Mexico City, chased down a small freight lorry carrying 44 oxygen tanks, after the lorry was reported stolen.
Two suspects were detained at the scene.
The thefts came as authorities launched a campaign urging people to return rented oxygen tanks they no longer need, saying enormous demand amid the pandemic has created a shortage of the cylinders.
The consumer affairs agency launched an online campaign under the slogan Return Your Tank, For The Love of Life.
With hospitals in Mexico City and other states overwhelmed by a wave of Covid-19 cases, many families have turned to treating their relatives at home with supplementary oxygen, creating spot shortages of tanks and oxygen for refills.
But once patients recover, the agency said, many people simply keep the canisters just in case someone else falls ill.
"By doing this they are depriving other patients of something they need at a given moment, and cannot get," the agency said.
Even those who have their own tanks must often wait in long lines and wait hours to get oxygen tanks filled.
Mexico has seen almost 1.67 million confirmed coronavirus infections and almost 143,000 test-confirmed deaths related to Covid-19.
With the country's extremely low testing rate, official estimates suggest the real death toll is closer to 195,000.
The country's defence department, meanwhile, said four doses of coronavirus vaccine were stolen at a public hospital in Cuernavaca, south of Mexico City, probably by a hospital employee or with the aid of an employee.
"This theft was able to be carried out through the dishonesty and greed of a member of the hospital's vaccination staff," the department said in a statement.
The army has been given responsibility for transporting and guarding vaccines in Mexico, but a private security firm was apparently in charge inside the hospital.
Before Tuesday, Mexico had received only about 750,000 doses of the Pfizer vaccine, and several people have been sanctioned for cutting lines to get doses.
Mexico's total amount so far is enough to vaccinate about half of the country's 750,000 front-line medical personnel, all of whom will need two doses.
Why are you making commenting on The Herald only available to subscribers?
It should have been a safe space for informed debate, somewhere for readers to discuss issues around the biggest stories of the day, but all too often the below the line comments on most websites have become bogged down by off-topic discussions and abuse.
heraldscotland.com is tackling this problem by allowing only subscribers to comment.
We are doing this to improve the experience for our loyal readers and we believe it will reduce the ability of trolls and troublemakers, who occasionally find their way onto our site, to abuse our journalists and readers. We also hope it will help the comments section fulfil its promise as a part of Scotland's conversation with itself.
We are lucky at The Herald. We are read by an informed, educated readership who can add their knowledge and insights to our stories.
That is invaluable.
We are making the subscriber-only change to support our valued readers, who tell us they don't want the site cluttered up with irrelevant comments, untruths and abuse.
In the past, the journalist’s job was to collect and distribute information to the audience. Technology means that readers can shape a discussion. We look forward to hearing from you on heraldscotland.com
Comments & Moderation
Readers’ comments: You are personally liable for the content of any comments you upload to this website, so please act responsibly. We do not pre-moderate or monitor readers’ comments appearing on our websites, but we do post-moderate in response to complaints we receive or otherwise when a potential problem comes to our attention. You can make a complaint by using the ‘report this post’ link . We may then apply our discretion under the user terms to amend or delete comments.
Post moderation is undertaken full-time 9am-6pm on weekdays, and on a part-time basis outwith those hours.
Read the rules here