​ISIS responsible for mass grave, atrocities, Iraqi villagers say

Yazidi villagers describe ISIS atrocities 03:02

In once peaceful farmland in northern Iraq, men showed us what they say is a mass grave. Eyewitnesses told us ISIS killed at least 50 Yazidi men at the site. Though we cannot verify what's buried under the mound of earth, they told us the men were shot one by one, and their shallow grave covered in dirt.

The site of an alleged mass grave containing the remains of at least 50 Yazidi men CBS News

Naif Ibrahim Hoda knew the men - he told me they were all from his village. He believes his uncle and two cousins lie dead beneath the soil.

Naif Ibrahim Hoda CBS News

Hoda told me he survived because he had left in the early morning before ISIS arrived. Later on, they blocked the road and everyone else was captured, according to Hoda.

The Yazidis were hounded from their homes by ISIS in August, fleeing to nearby Mount Sinjar where they faced starvation. It's thought thousands of Yazidi women were kidnapped and enslaved by the extremists.

They can't give the bodies here a proper burial, because the front line is just a few hundred yards away, and ISIS still holds the next village.

Kurdish fighters - known as the peshmerga - are slowly clawing back territory from ISIS. They believe they can defeat the extremists, and prevent more massacres. But they're outgunned by the militants - and frustrated with their American allies.

A Peshmerga fighter aims his rifle on the front line CBS News
What the fighters facing ISIS want from the U... 02:49

"We have lost more than 1,000 peshmergas, and somewhere around 5,000 have been wounded," said Kurdish National Security Adviser Masrour Barzani.

Barzani told us 70 percent of those deaths were caused by car and roadside bombs - and many of them could have been prevented if his men had armored vehicles. They've asked Washington for several hundred and have been given just 25.

"Of course they all praise the peshmergas and thank us, but that is not enough," said Barzani. "We need the equipment."

"What do you say to the families of those men who have died?" I asked him.

"These are our heroes, and we need to protect these heroes, and I think they're the heroes of the free world, and it's the responsibility of the international community to protect them."

President Obama is expected to go to Congress this week to ask for new authorization for the use of military force against ISIS. The authorization is expected to set a limit on the length of the conflict - and will surely spark a debate on whether U.S. ground troops should be deployed.