Worldwide, an unprecedented 363 million children and youth are affected by closures of schools and universities, according to data released by this week by the United Nations' education agency UNESCO.
That number is expected to rise as more countries implement lockdowns.
"The global scale and speed of the current educational disruption is unparalleled and, if prolonged, could threaten the right to education," UNESCO Director-General Audrey Azoulay said in a statement.
As countries deal with the situation, it is important to "ensure this crisis promotes innovation and inclusion and does not exacerbate learning inequalities," she said.
Schools are deploying distance-learning programmes and education applications and platforms, including radio and the internet to reach students remotely.
But the so-called "digital divide" - which refers to the gap between those who have access to computers and the internet, and those with limited or no access - is a challenge.
About 54% of the global population - or 4.1 billion people use the internet. But only two out of 10 in the least developed countries are online, according to the International Telecommunication Union (ITU), the U.N.'s internet and telecoms agency.
"Digital exclusion in general reflects and entrenches broader patterns of disadvantage across age, gender, social and economic dimensions," said Julian Thomas, a communications professor at Australia's RMIT University.
"The cost of internet access can be prohibitive for low-income families, and the infrastructure and services necessary for everyone to be able to use the internet at home is unevenly distributed across urban, rural and remote areas," he said.
Low-income families are particularly dependent on mobile devices for internet access, which may not be suited for learning purposes, he told the Thomson Reuters Foundation.
Those families also tend to rely on schools, libraries, workplaces and community centres for internet access, and are "substantially disadvantaged" when these are closed, he said.
In India, where primary schools in Delhi, and schools and colleges in Kerala state are closed until April to fight the spread of the coronavirus outbreak, education charities say they are worried about girls dropping out.
Nearly a fourth of the country's girls leave school before puberty, with the result that the female literacy rate is 66% compared to 80% for men, according to census data.
In Delhi, the closure coincides with the holiday period. If it extends beyond March 31, then parents may be involved in lessons, and some classes may be moved online, said Shailendra Sharma, principal advisor at the directorate of education.
"We recognise that in government schools, many students are first-generation learners, so parents may not be able to help much. Nor does every student have access to a smartphone or tablet," he said.
"So there may be challenges if the shutdown lasts longer." - Reuters