— The mass killings of Sunni tribesmen battling the Islamic State have added urgency to Iraqi government efforts to support pockets of resistance against the militants. But distrust, a lack of financing and corruption threaten the process, tribesmen and officials say.

In a flurry of meetings in recent weeks, tribal leaders have demanded that Prime Minister Haider al-Abadi address problems of missing weapons and lack of support as they hold out against extremists in the face of mass detentions and executions. Hundreds of tribesmen have been summarily executed in the western province of Anbar over the past month, with hundreds more rounded up north of Baghdad.

The slayings have underscored the predicament of Sunni tribes that have resisted Islamic State extremists, often with little help from the central government. The killings threaten to undermine the government strategy of mobilizing the Sunni tribes against the Islamic State in the tribes’ areas — a key pillar in efforts to crush the militants.

“We demand that the government does something,” said Sheik Naim al-Gaoud, a tribal leader with the Albu Nimr. “We feel that we have been abandoned and neglected.”

The Albu Nimr tribe held out against the insurgents in Anbar for 10 months before caving to them in late October. Many tribal fighters fled, but others were rounded up and later killed in public, tribesmen say. Albu Nimr leaders and the government put the number executed at more than 320.

Iraqis attend a gathering of Shiite and Sunni tribal leaders and clerics in Baghdad to discuss support for Sunni tribes in their fight against the Islamic State. (Ahmad Al-Rubaye/Agence France-Presse via Getty Images)

Tribal leaders fault the government for not providing more support, and they also cite underlying distrust and corruption stemming from the tenure of former prime minister Nouri al-Maliki. U.S. military leaders have said the Iraqi army lacks the capacity to go to the aid of the tribes.

Gaoud said the tribe did receive some arms: 30 PK-C machine guns and 15,000 rounds of ammunition Jan. 15, two weeks after the Islamic State seized control of Anbar’s two main cities. Little has been received from the Iraqi army since, he said, save for an airdrop of 50,000 rounds of ammunition during the summer.

“There is corruption. Those that are meant to be delivering us ammunition are selling it on the black market, and we instead are forced to buy it,” he said. “There are so many corrupt officers.”

Gaoud said a meeting with Abadi two weeks ago resulted in promises, but there are concerns over whether the pledged support will be forthcoming. “They said they have supplied so many arms to Anbar, but nothing arrives because of corruption, and they are investigating,” he said.

Abadi has been trying to address graft in the army since taking power in September and forcing senior officers into retirement, but U.S. officials and analysts say mismanagement runs deep.

Money is also a problem in arming the tribes, Iraqi officials say, adding that the funding problem is likely to worsen. Iraq’s economy, hit by falling oil prices, will shrink by 2.7 percent in 2014, the International Monetary Fund has said.

“We are not sure that the government will effectively be able to help them, because of the shortage in financing,” said Ahmed Mahjoob, an adviser to Salim al-Jubouri, the Sunni speaker of parliament who has facilitated meetings between the government and tribesmen.

Although the tribes are crucial to the strategy to turn back militants, efforts so far to build their fighting forces have been limited. In the refugee camps of Irbil, tribal sheiks have gathered the names of men willing to fight, but they complain that a lack of trust between the Shiite-led government and the Sunni tribes impedes efforts.

In the Bakhira camp, a bleak tangle of tents on the edge of the capital of Iraq’s semiautonomous Kurdish region, young men say they are desperate to fight to help free themselves and their families from the grim realities of life in the camp.

“We don’t want money. We don’t want anything — just give us weapons and we will go,” said Faisal Obaidi, 30. “There are so many of us here who feel the same.”

Many of those who once served in the police force of Mosul, a city overrun by the Islamic State in the summer, have already been recruited from the refugee camps and are in a training camp called the Mosul Liberation Camp.

Former Mosul police chief and camp commander Khalid Hamdani said he has more than 4,000 recruits awaiting arming and training. Some observers are dismissive of the efforts, which are overseen by Atheel al-Nujaifi, former governor of Nineveh province, of which Mosul is the capital.

“They have three Kalashnikovs between them,” joked Firas Qusai, a 25-year-old from Mosul at the Bakhira camp, who has friends who left to join the military camp.

Hamdani said the process of setting up the camp, which opened just over two weeks ago, has been slowed by red tape because officials need to negotiate with both the Kurdish and central governments, whose relations are strained. Hamdani said he hopes to receive his first supplies of equipment from Iraq’s Interior Ministry next week.

Internal disputes also have hampered progress, officials say. Nujaifi is a divisive figure whom some partly blame for the collapse of Mosul in the face of militants because he was governor of Nineveh province at the time.

Other members of the provincial council boycotted a recent meeting with the prime minister in Baghdad, saying they protested Nujaifi’s presence.

“Next week, we the tribes of Nineveh will hold a meeting to discuss the operation to liberate Mosul,” said Mahjoob. “All this is being done without Nujaifi.”

Sheik Abdullah al-Yawar, a leader of the powerful Shammar tribe, said he has become one of the government’s main interlocutors. The Shammar, like other tribes, have gathered fighters in the Kurdish region but are awaiting arms and training.

“The prime minister is committed that full support should be provided,” said Rafid Jaboori, a spokesman for the prime minister’s office. “The tribes are essential strategically, but it’s complicated. It’s war.”

Over the past two weeks, the Abadi government has met with at least five tribal delegations from Anbar, Nineveh and Salahuddin, he added.

“Until now, we haven’t really seen any support from the Kurdish or Iraqi government,” said Sheik Khalid al-Shammari, another tribal leader. “We were asked to gather names for one battalion, 350 to 400 people. . . . We’ve done that and submitted it weeks ago, but we’ve heard nothing.”

In the meantime, pressure is mounting. Hundreds of members of the Jabbour tribe have been rounded up in al-Alam, 100 miles north of Baghdad, accused of mounting a coup against the Islamic State there, tribal leaders said.

“It’s never too late,” said Gaoud. “But every day we have executions. Every day is a bloodbath.”