The United Nations (UN) on Sunday urgently called upon all parties to keep everyone - including children and young people - safe on the roads and safe from any kind of violence.

"UN agencies are increasingly concerned for the safety of children and young people caught up in recent protests over road safety in Dhaka and other parts of the country," the UN office in Dhaka said in a statement shared on its official Facebook page.

It said students and young people have a legitimate right to speak out on issues of concern to them including road safety issues and to have their opinion heard without the threat of violence.

The UN has long campaigned for better road safety across the world and traffic accidents in Bangladesh are one of the major killers of young people (according to a World Health Organization report there are more than 20,000 road fatalities every year in Bangladesh).

"We are deeply concerned about the reports of violence and call on all for calm. The concerns expressed by youth about road safety are legitimate and a solution is needed for a mega city like Dhaka," said United Nations Resident Coordinator Mia Seppo.

She said a functioning public transport system should ensure the safety of all, including children, young girls and women.

The UN statement said it is a matter of deep concern that a number of young people taking part in demonstrations in the capital have been injured over the last few days.

Many schools have been closed as a result of the protests, depriving children of learning opportunities, it said.

The US Embassy in Dhaka also said "nothing can justify the brutal attacks and violence" over the weekend against the thousands of young people who have been peacefully exercising their democratic rights in supporting a safer Bangladesh.

The Embassy, in a Facebook post, also said they also do not condone the actions of a few who have engaged in senseless property destruction, including of buses and other vehicles.

The peaceful demonstrations of the past week in favor of better vehicle and road safety, led by students and school children across Bangladesh, have united and captured the imagination of the whole country, it said.

Several thousand university students on Sunday blocked Shahbagh intersection, one of the city's busiest areas, protesting Saturday's attacks on school and college students in Jhigatala during their demonstrations demanding safe roads.

Students of Dhaka University, Dhaka Medical College and Hospital and Bangladesh University of Science of Technology (Buet) started gathering at the intersection around 11 am and blocked the road, disrupting vehicular movement.

At least seven photojournalists were injured in attacks by unruly youths in Jhigatala and Science Laboratory areas of the city on Sunday while taking snaps of an attack on protesting students.

The injured were identified as AM Ahad of international news agency the Associated Press (AP), Zawad of the Daily Janakantha, Palash of the Banik Barta, Rimon of US-based Zuma Press, Sharif of the Dainik Naya Diganta, freelancer Rahat and Enamul Hasan, a photography student of Pathsala South Asian Media institute.

Witnesses said a group of youths, allegedly Bangladesh Chhatra League activists, equipped with sticks swooped on some photojournalists in the two areas around 1:30 pm while performing their duties, leaving seven of them injured.