When Ibro Begic decided to tackle the hazardous mountain road to reach those stricken by record floods near his Bosnian town, he was also challenging deep ethnic divisions left over from the brutal conflict of the 1990s.

When news reached him last week that the Serb-populated town of Doboj had been inundated, Begic immediately called on 10 friends to put together a relief operation.

It was a generous move, made remarkable by the fact that Begic is a Bosnian Muslim and a former soldier who fought the Serbs during the country's horrific civil war between 1992 and 1995.

"During the war, we were in enemy armies," he told AFP. "But the war is history. Humanity is something else."

Having gathered supplies including milk, sheets and rubber boots, Begic set off along the mountain pass -- the only road still open to Doboj from his town of Tesanj in central Bosnia.

He says the response he received from the Serbs in Doboj, one of the worst-hit towns where at least 20 people have died or are missing from the floods, was immense gratitude mixed with "shock".

"God asks us all to help each other in need. I am certain that the Serbs would do the same," Begic said.

- 'A turning point' -

It is certainly not the only instance in Bosnia where the difficult legacy of the war -- which has left the country politically divided between Serbs, Croats and Muslims -- was put to one side during the devastating flooding of the past week.

The small town of Zepce, around 30 kilometres (18 miles) further south from Tesanj, is mostly populated by Croats.

When a stream of Muslims began to arrive here from villages dotted around the region, few expected a warm welcome. The experience was a painful reminder of the war when tens of thousands were expelled from their homes by both Croats and Serbs.

But this time around, they were met with nothing but friendship.

A local high school gym in Zepce was ready to shelter the first group of evacuees from the Muslim village of Zeljezno Polje.

One of the villagers, Elvir Cizmic, a soldier during the war, told AFP: "Honestly, I did not expect such a solidarity. In just a few hours, people brought food, clothes and offered their homes to the families."

Around 30 to 40 people, mainly elderly women, were sheltering in the school when AFP visited, while dozens of young volunteers moved between them offering assistance.

"No one asked us for our name or our religion. They helped us in a way that I would not expect even from Muslims," Hanifa Masic, a 68-year-old evacuee, told AFP.

She hugged one of the young volunteers, a Croat called Ivana Grlic, who looked happy to help.

For Cizmic, the disaster marks a "turning point in relations between the three communities".

"I believe it will greatly help to regain trust between the people who had been pushed into the war," he said.

- 'Solidarity' -

Like nothing else in the past two decades, the natural disaster has allowed people to ignore the divisive nationalism spouted by many of their political leaders.

Even Milorad Dodik, the fiercely nationalist president of the Bosnian Serb entity, had to express his gratitude to the Muslims who came to help their Serb neighbours in the northern town of Samac.

"I thank you on behalf of all residents of Samac to whom aid was brought by the (mainly Muslim) town of Gradacac, which provided inflatable boats and rescuers," Dodik said.

The compliment was returned by Edhem Camdzic, an Islamic mufti from the northern town of Banja Luka, who said he had come across an "honourable man, a Serb, who has been rescuing people with his inflatable boat regardless of their ethnicity" during a tour of Muslim villages.

"Amid this tragedy, I am so delighted to see this solidarity between people who generously helped each other," said Camdzic.

More than a quarter of Bosnia's 3.8 million population has been affected by the worst floods in a century.

The Bosnian war claimed some 100,000 lives and displaced two million people, almost half the country's pre-war population.