The death toll from flash floods that swept through an Afghan city climbed to 100 Wednesday, officials said, as rescue workers searched for survivors in the rubble of collapsed houses.

Afghanistan's disaster management ministry said another 100 people had been injured and nearly 500 houses destroyed when torrential overnight rains fuelled floods that ravaged the city of Charikar, north of the capital Kabul.

Rescue workers in Afghanistan searched Wednesday for survivors of flash floods that killed more than 70 people and destroyed hundreds of houses in a city north of the capital, officials said.

Troops pulled dozens from the rubble of collapsed buildings in Charikar, capital of Parwan province, after it was hit by heavy rain overnight, but officials and witnesses said many children were among the dead. 

Mohamed Qasim, a 45-year-old farmer from the city, told AFP that 11 members of his family were killed in the floods. 

Piles of rocks from destroyed buildings were scattered across the city, with roads blocked by mud and debris and cars flipped on their side.

"The figures we have collected from hospitals show that 72 people have died and over 100 are injured wounded," said Ministry of Disaster Management spokesman Tamim Azimi. 

Waheeda Shahkar, spokeswoman to the Parwan governor, confirmed the toll, adding that more than 500 houses had been destroyed. 

In parts of the city anxious residents gathered to see if any relatives would be pulled from the wreckages by rescue workers using heavy machinery. 

Many people stood on rooftops as rain continued to lash the city, holding on to their salvaged belongings. 

Emergency relief ordered 

"I was alone when the flood hit. I grabbed the window and was holding it for two hours until the neighbours came to rescue me," said 70-year-old Hamida. 

"I lost everything, my jewelry, money and all my property."

Flash floods were also reported in other provinces -- including Nangarhar, Panjshir, Wardak, Loghar, Paktika and Kapisa -- but there were no reports of casualties, the ministry of disaster management said.

Torrential downpours and flash floods kill scores of people annually in Afghanistan.

Many poorly built homes, mostly in rural areas, are at risk of collapse during the rains in the impoverished country.

Earlier this month, 16 people, including 15 children, were killed and dozens of houses were destroyed when flash floods ravaged a village in the eastern province of Nangarhar.

Heavy monsoon rains have also wrought havoc on neighbouring Pakistan, with authorities in the southern city of Karachi reporting 30 deaths over the past three weeks from flood-related incidents, including injuries from collapsed buildings, drownings and electrocutions.

President Ashraf Ghani had ordered emergency relief to be sent to Charikar, the presidential palace said in a statement.