Growing outrage provoked by night raids on suspected insurgents is jeopardising US strategy for withdrawing from Afghanistan by the end of 2014, researchers have warned.

The claim comes as Hamid Karzai, Afghanistan president, prepares to visit Washington on Tuesday.

He has frequently criticised the raids, often conducted in villages belonging to his ethnic Pasthun community.

The US military has sharply expanded raids on homes where militant commanders are suspected to be hiding, hoping to weaken the Taliban to the point where Afghan security forces are capable of standing alone.

But the Open Society Foundations, a human rights group, issued a report on Monday that questioned whether the resentment caused by the operations may outweigh the benefits they deliver in terms of removing militants from the battlefield.

“A dramatic upsurge in night raids in the last year has brought Afghan anger on this issue to a boiling point,” the report said. “Without more transparency or supporting evidence, it is difficult to balance the purported benefits of night raids with their very real and obvious costs.”

The issue has emerged as a sticking point in negotiations between Kabul and Washington on a long-term “strategic partnership” agreement to define the terms of US basing rights and future military and economic aid.

Night raids typically involve US and Afghan troops descending on homes from helicopters or surrounding them in vehicles before conducting searches that often leave occupants feeling humiliated. Although the US military has taken steps to reduce the harm they cause, the raids have sparked protests in several areas.

The report quoted a man from the eastern Nangarhar province as saying of the raids: “They claim to be against terrorists but what they are doing is terrorism. It spreads terror. It creates more violence.”

The debate over the raids is important because it cuts to the core of the Obama administration’s strategy for containing the Taliban while simultaneously reducing its 100,000-strong troop presence in response to political and budgetary pressures at home.

Two years ago, US generals recommended that the White House adopt a broad counter-insurgency strategy to push back Taliban advances by making priorities of protecting the population and building up the Afghan state.

The weight of the Pentagon’s effort has since shifted increasingly towards a narrower counter-terrorism approach that hinges on increasing “kill-or-capture” raids while rapidly expanding Afghanistan’s army and police.

The report said the pace of raids had increased five-fold between February 2009 and December 2010. Some 1,700 raids were conducted in a three-month period from roughly December 2010 to February 2011, the most recent period for which data were available.

The report quoted a senior US military adviser as saying in April that as many as 40 raids might be taking place in Afghanistan each night.

The authors said that US forces had taken significant steps to mitigate the anger caused by the raids in the past year, including boosting intelligence-gathering to reduce incidents of wrongful targeting and improving co-ordination with Afghan officials.

But they found that the sheer increase in the scale of the night operations meant these measures were having a limited impact in changing Afghan perceptions.

Researchers argue that the resentment the raids still cause risks driving a wedge between locals and US and Afghan forces that could be exploited by insurgents.

The deaths of four people in a night raid in Takhar province in May triggered a protest by more than 2,000 people that lasted several days and culminated in an attempt to storm a local international military base, the report said.

The US military believes that the raids are causing severe damage to insurgent networks, disrupting their ability to stage attacks which often harm civilians.

This campaign has, however, yet to translate into a reduction in civilian deaths in Afghanistan, which have hit new highs this year, according to UN data.

The impact of the strategy has been blunted by the Taliban’s ability to exploit safe havens in Pakistan, which does not officially allow US forces to conduct raids on its territory.

The US has blamed the Haqqani network, which has sanctuaries in the Pakistani enclave of North Waziristan, for a series of attacks on Kabul, including a raid last week in which attackers fired rockets at the US embassy and battled police during a 20-hour siege of a half-constructed building.