The US government has been secretly supporting a Pakistani militant group that has staged a series of deadly attacks against Iran, ABC News reported, citing unnamed US and Pakistani intelligence sources.

The group, known as Jundallah, or "God's Brigade," is made up of members of the predominantly Sunni Muslim Baluchi tribe which inhabits Pakistan's gas-rich province of Baluchestan, as well as neighboring regions in Iran and Afghanistan. In their exclusive report, which aired on Tuesday evening and was posted online on Wednesday morning, ABC News reporters Brian Ross and Christopher Isham said that while the US provides no direct funding, the group has been "secretly encouraged and advised" by the American government since 2005.

U.S. officials say the U.S. relationship with Jundullah is arranged so that the U.S. provides no funding to the group, which would require an official presidential order or "finding" as well as congressional oversight.

Tribal sources tell ABC News that money for Jundullah is funneled to its youthful leader, Abd el Malik Regi, through Iranian exiles who have connections with European and Gulf states.

Jundullah, which claims that Iran's Shiite regime is oppressing its Baluchi minority, has claimed responsibility for bombings, kidnappings, and televised beheadings that have killed more than a dozen Iranian troops and officials. In February the group said it carried out a car-bomb attack targeting Iran's Revolutionary Guard in Zahedan, the provincial capital in southeastern Iran, killing 11. Jundullah's leader Mr. Regi, who founded the group in 2003 at the age of 23, has – according to ABC – admitted to personally executing captured Iranian soldiers.

"He used to fight with the Taliban. He's part drug smuggler, part Taliban, part Sunni activist," said Alexis Debat, a senior fellow on counterterrorism at the Nixon Center and an ABC News consultant who recently met with Pakistani officials and tribal members.

"Regi is essentially commanding a force of several hundred guerrilla fighters that stage attacks across the border into Iran on Iranian military officers, Iranian intelligence officers, kidnapping them, executing them on camera," Debat said.

The ABC News report said US Vice President Dick Cheney spoke to Pakistani President Pervez Musharraf about Jundullah and its campaign against Iran during Mr. Cheney's surprise visit to Pakistan in February. When asked by Reuters about the meeting, a Cheney spokeswoman said, "We don't discuss conversations between the vice president and foreign leaders." Reuters also quoted a CIA official as saying the ABC "account was not accurate."

An analysis by Strafor, a global intelligence consulting firm based in Texas, noting that Jundullah has stepped up its attacks recently, says that the US could be using Jundullah as a "poking device" [subscription only] against Iran.

U.S. support for Jundallah fits into the larger picture of U.S.-Iranian negotiations over Iraq. Iran has made painfully clear that it has -- and can use -- a variety of militant assets throughout the region to pressure Washington to meets its demands in Iraq. At the same time, the United States has an interest in demonstrating that it has friends among Iran's minority groups to gather intelligence, stir up public unrest and distract the clerical regime from its Iraqi agenda.