Christian aid agencies say the destruction of transport and communication links is leaving many victims of Pakistan's deadly floods virtually "cut off" from outside help.
The country has been hit by the worst monsoon flooding on record. At least 1,400 people have been killed and hundreds of thousands have been left homeless.
A state of emergency has been declared in one of the worst hit areas, Khyber Pakhtunkhwa, where heavy rains have swept entire villages away and killed at least 1,000 people.
U.K.-based Tearfund, which has been monitoring the situation, said in a report that swollen rivers had burst their banks and deluged many areas, destroying roads, bridges, crops and livestock. Its partner, SSEWA-PAK, has begun distributing food and essential items to families affected by the flooding.
"It's one of the biggest floods in the history of Pakistan. People need food immediately as they have lost their homes and possessions," reported Ashraf Mall, Tearfund's Country Representative for Pakistan.
"But it is not proving easy to respond to this emergency," Mall added. "Bridges and roads have been destroyed and the disruption of transport and communication links is making assessments difficult, with many survivors effectively cut off from outside help."
Action by Churches Together Alliance (ACT), meanwhile, said thousands of people made homeless by the floods in the southern province of Balochistan are still waiting to receive aid more than a week after the region was first hit by rising waters. It complained that Balochistan was being left out as aid efforts concentrate on the badly hit northern provinces.
In a situation report released Monday, ACT said military troops had rescued more than 20,000 people but rescue workers were still struggling to save at least 27,000 people still stranded by the water.
"With water levels remaining high and communication systems severely damaged, the rescue of thousands of trapped people and the delivery of aid will lead to further loss of life," reported the global alliance of churches and related agencies.
ACT is planning a three-month crisis phase response that will provide food, shelter and medicine to more than 50,000 people in Balochistan and Khyber Pakhtunkhwa.
Another group on site, Church World Service Pakistan, has begun distributing 1,000 food and temporary shelter kits in Balochistan, as well as providing emergency healthcare through mobile health units.
On Tuesday, floodwaters surged into Pakistan's heartland and swallowed dozens of villages, adding to a week of destruction that has already ravaged the mountainous northwest.
The government has struggled to cope with the scale of the disaster at a time when it is grappling with a faltering economy and a brutal war against the Taliban.