Right-wing organisations, including banned extremist groups, are leading the relief and rescue effort in flood-hit Pakistan.
Three of the most prominent groups, Jamaat-e-Islami, Jamaat-ud-Dawa and Sipah-e-Sahaba have thousands of activists who have fanned out across the country.
All are very powerful on the ground despite having limited or no officially recognised political representation.
Their relief effort comes as Pakistan's government is dogged by accusations that it has been slow to respond to the crisis.
More than 1,600 people have died and 14 million have been affected by the worst floods in Pakistan's history.
"We have 100,000 activists deployed in flood-affected areas across the country," says Naimatullah Khan, head of the Al-Khidmat (The Service) organisation, the social welfare wing of the Jamaat-e-Islami, Pakistan's largest and most influential right-wing political party.
The party is a staunch opponent of Pakistan's military co-operation with the US and favours "reconciliation" with the Taliban in Pakistan and Afghanistan.
It is now one of the most active out of dozens of Islamic groups operating in the disaster zone.
Mr Khan says that Al-Khidmat is currently providing emergency relief and rescue operations in 46 districts across Pakistan.
"We serve cooked food as well as packed rations," he says.
"The biggest problem is the lack of drinking water, which is also creating diseases.
"For this reason we are sending water purification plants to the areas and medical camps with doctors and stocks of medicine have been set up. We also have 60 ambulances operating in the affected areas."
But the Jamaat is not the only Islamic group operating here.
The Jamaat-ud-Dawa Islamic charity is also running a highly effective relief effort.
The group has been accused of being a front for the Lashkar-e-Taiba jihadist group, which is accused of carrying out the 2008 Mumbai (Bombay) attacks in which 166 people were killed.
Jamaat-ud-Dawa denies the charges against it.
'Trapped by water'
"We have 3,000 people deployed [in the provinces of] Sindh, Punjab, Khyber Pakhtunkhwa and Balochistan," Yahya Mujahid, spokesman for the group, told the BBC.
"In Punjab, we have been involved in everything from providing relief to directing traffic and clearing blocked roads.
"We have used tractor trolleys to get people across roads that have caved in and boats are being used where people are trapped by the water.
"So far we have established 13 relief camps to provide shelter. We have also set up stalls where cooked food is distributed across the affected areas."
The group boasts 16 mobile medical camps - staffed by doctors and medical aid workers - complemented by 40 ambulances, "to provide aid where it is needed most".
Mr Mujahid said thousands of people had been provided with relief by Jamaat-ud-Dawa so far.
Yet Another organisation active in the relief effort is the banned Sipah-e-Sahaba (SSP).
This is considered the most extremist of Pakistan's right-wing religious groups - it deems all non-Sunnis as non-Muslims.
Its splinter group - the Lashkar-e-Jhangvi (LJ) - is Pakistan's deadliest militant group.
The SSP, however, denies it has any links to the LJ.
Its leaders say their struggle has always remained within the bounds of the law.
Maulana Mohammad Ahmed Ludhianvi, the president of SSP, says: "As you know we have been listed as an 'especially' banned organisation.
"The authorities always say no to us. But we feel this is a disaster which needs the efforts of all Pakistanis.
"Therefore I have ordered our activists to carry out relief activities without identifying ourselves. Hundreds of them are now helping to evacuate flood victims across the country."
Mr Ludhianvi says that the SSP has in addition set up relief camps and is distributing food and supplies to the homeless.
"I have told my activists to collect information first, and then arrange for supplies - as the requirements differ from place to place," he said.
He says that the SSP is "particularly active" in South Punjab and Khyber Pakhtunkhwa.
"We have been in the forefront of relief activities in Jhang, Layyah and Muzzaffargarh," he says. "Our activists were also among the first to arrive on the scene in Peshawar and Nowshera.
"In Nowshera in particular, we have distributed a great deal of relief goods.
"I must also add that the Punjab government has been particularly effective in handling the situation."
But the leaders of the other two groups do not agree with this assessment.
"I don't know about elsewhere - but the government has not been very visible in relief activities here," says Jamaat-ud-Dawa spokesman Yahya Mujahid.
"There is a lot of anger against the authorities."
He was speaking from Muzaffargarh, where a federal minister was attacked on Sunday.
Mr Mujahid says that anyone wanting evidence of public anger against the authorities need look no further than local media reports.
"Have you heard the victims praising the official relief effort so far?" he asks.
Al-Khidmat head Naimutullah Khan agrees.
"The authorities only issued warnings to evacuate the affected areas - and even these were too late in some places," he said.
"After that, most have been left to deal with the situation on their own."