More than 200,000 Afghan refugees have been repatriated from Pakistan this year, nearly half of them in September alone, UNHCR said Tuesday, the highest number since 2002, after the fall of the Taliban regime.

The tsunami of refugees returning to the war-torn country comes after Pakistan tightened its border controls in June and began cracking down on undocumented Afghans.

The vast majority -- more than 185,000 -- returned after July, with nearly 98,000 crossing the border in September alone, UNHCR spokesman Qaisar Khan Afridi told AFP.

"From January until today, the number of refugees voluntarily repatriating to Afghanistan has crossed the figure of 200,000," Afridi said.

More and more appear to be going every day, with officials saying that the first four days of October saw up to 5,000 returnees daily.

An Amnesty International report Tuesday said Pakistan hosted 1.6 million refugees, making it the third largest refugee hosting nation in the world.

But UNHCR said the figure, based on its own data, was already out of date and should be revised to 1.4 million after the movement since July. A further one million undocumented refugees are estimated to be in Pakistan.

Since 2009, Islamabad has repeatedly pushed back a deadline for them to return, but fears are growing that the latest cutoff date in March 2017 will be final.

Pakistani officials said the increase came after they vowed to tighten border controls, particularly at the porous Torkham Gate crossing.

However UNHCR cited an array of other reasons that could be helping drive the rush back into Afghanistan, including increasing anxiety and insecurity for refugees about life in Pakistan.

Other factors include the UNHCR decision to double its cash grant for voluntary returnees from $200 to $400 per individual in June, and a campaign by the Afghan government to lure its citizens back with the slogan "My country, my beautiful country".

In Afghanistan, however, torn apart by more than three decades of conflict, authorities warn the number of displaced people has outpaced the capacity of the government and aid agencies to cope.

Meanwhile the EU said Monday it has struck a tentative deal with Afghanistan to take back migrants ahead of a conference in Brussels aimed at securing international financial aid for the war-ravaged nation.

However, European Union officials have denied that aid pledges would depend on the Kabul government accepting the return of tens of thousands of Afghans from an overstretched Europe.