(VOVworld) - Greece has seen a record 48,000 migrants and refugees land on its shores in the past five days, the International Organization for Migration said on Friday.

A boat carrying migrants and refugees arrives at the Greek island of Lesbos from Turkey on October 21, 2015. (Photo: AFP/Aris Messinis)

Amin Awad, the Middle East director for UN refugee agency UNHCR, said Russian air strikes and increased fighting around the Syrian city of Aleppo has contributed to the refugee exodus to 50,000 people.

The news agency ANSA reported that more than 40,000 migrants overflowed to Slovenia since Hungary closed its border with Croatia last Saturday.

On Friday, Serbia and Croatia agreed to increase the flow of asylum-seekers over their border after thousands were forced to spend a muddy night out in the open in near-freezing temperatures.

The two nations' interior ministers said they will start shipping migrants by train directly from Serbia to Croatia so they won't have to cross on foot.

The same day, Germany said it will tighten refugee rules to deal with the increasing flows of migrants from war-torn countries like Syria. Germany is considered an ideal destination for migrants mainly from Turkey and Balkan countries.