GENEVA, June 8 (Xinhua) -- An increasing number of migrant children are being expelled to Niger as countries across Europe and North Africa seek to curtail irregular migration, the UN children's fund UNICEF said Friday.

There are insufficient cross-border mechanisms to protect these children from the many risks they face: trafficking, violence, abuse, exploitation and detention.

"We are seeing clampdowns on migration from across Europe into North Africa and now farther south with a big spike in forced returns recently," said Sarah Crowe, UNICEF's spokesperson on migration in Geneva, who recently returned from Niger.

Since November last year, more than 8,000 West Africans, including 2,000 children, have been returned to Niger from Algeria, while another 900 registered refugees and asylum seekers from countries in East Africa have been transferred to Niger for processing from Libya.

At the same time, migrant flows into Niger continue.

"Children, nursing mothers, young women from many parts of West Africa left in scorching heat, are pushed from pillar to post as one country after the next makes them someone else's problem," Crowe told Xinhua.

She said the answer is robust systems that keep children safe across all borders north, south, east and west, with better investment to poor countries like Niger facing the brunt of this.

In April alone, there was an increase of 14 percent over the previous month in people transiting through Niger -- a rate of nearly 500 a day with around a third being children, UNICEF spokesperson for Refugees and Migrant Crises Sarah Crowe said in Geneva.

Crowe said most of them are exhausted and have been exposed to violence or left without adequate support and protection.

The true figure is likely to be higher as many children go undetected or hide.

UNICEF said that with government negotiations on the Global Compacts for Migration and Refugees currently underway in the UN system, UNICEF is calling for solutions to keep children safe.