Tajikistan border guards said Wednesday that 347 refugees from Afghanistan had crossed into the Central Asian country over two days, fleeing sweeping gains by Taliban fighters as foreign forces withdraw.

State information agency Khovar, citing a border guard report, said the refugees had "fled from the Taliban to save their lives," adding that two babies died during the border crossing.

The militants in recent weeks have brought huge swathes of the country under their control as foreign troops draw down, including Afghanistan's main Shir Khan Bandar border crossing with Tajikistan.

They claimed Wednesday to have taken a the strategic border crossing of Spin Boldak on the frontier with Pakistan.

Tajikistan said the refugees, who included some 64 boys and 113 girls, had crossed from Afghanistan's Badakhshan province, brining with them herds of livestock.

"Tajik border guards, guided by humanistic principles and good neighbourliness, allowed Afghan refugees to enter," they said in a statement carried by Khovar.

It said the group of Afghans were being accommodated in two sites in the mountainous Murghab region in the east of the ex-Soviet country.

The border guard said they had confiscated more than 3.5 kilograms of narcotics from the Afghans crossing into Tajikistan.

They added in the statement that the refugees had brought with them livestock, including 300 yaks, thee camels and 30 horses.

The border guards said the situation along the shared frontier with Afghanistan was under control.