Belgrade (AFP) - Some 300 migrants in Belgrade, mostly young men from Afghanistan and Pakistan, on Friday began a hunger strike and set off on foot towards the Hungarian border in the hope of entering the European Union.

Defying afternoon heat, the migrants began their 200 kilometre (120 mile) trek north escorted by a police car, an AFP photographer reported.

They were carrying blankets and backpacks, many bearing the distinctive blue logo of the UN refugee agency (UNHCR).

Some covered their heads with wet towels to keep cool as temperatures rose above 30 degrees Celsius (86 degrees Fahrenheit).

Abdul Malik from Afghanistan said the group was "going to Hungarian border."

"We're gonna change something by walking and not eating," he said.

"We are today in hunger strike. We don't want to eat. We didn't come here for the food, we are not hungry people," the 24-year old said.

"The only things we don't get in our country is security and education. That's the only thing we want to find here," he said.

The number of migrants blocked inside Serbia has grown significantly since Hungary introduced tough new measures aimed at stopping them crossing the border earlier this month.

According to UNHCR in Serbia, some 2,800 migrants were in the country on Friday, mostly in makeshift along the Hungarian border.

Malik said he had spent 20 days in Belgrade, sleeping in a park, but than decided to move on.

"I really appreciate Serbian people, they are really nice with refugees, the only problem we have right now is with Hungary," he said.

He explained that there were no children and women in the marching group "because they can't walk so just young men and some old people."

The men carried cardboards with messages reading "Stop wars if you want to stop refugees," "Hungary remove dogs from your border" and "Prove that humanity is still alive."

Serbia lies on the so-called Balkan route taken by hundreds of thousands of migrants from the Middle East, Asia and Africa since last summer on their way to western Europe.

Although the route was effectively shut down in March, migrants have continued to cross the region in smaller numbers, often with the help of smugglers.

Last weekend Belgrade decided to launch joint police and army patrols to beef up its borders against migrants.

Serbian authorities said recently that 102,000 migrants had been registered since the start of the year -- more than 500 a day.