KABUL – A second helicopter crash in a week Saturday claimed the life of one member of the U.S.-led coalition in Afghanistan, adding to the mounting losses experienced by coalition troops this past week.

According to officials in Kandahar province, the two-person OH-58 Kiowa helicopter crashed in the Daman district in the early evening hours Saturday.

Officials from the International Security Assistance Force said they have no indication that the helicopter was brought down by enemy activity in the area. Investigators will review the flight record to determine what caused the crash, to include possibilities such as mechanical or pilot error, an ISAF Joint Command official said.

On Monday, a Black Hawk helicopter crashed outside of Kandahar city, killing five U.S. servicemembers, all with the 3rd Combat Aviation Brigade, 3rd Infantry Division, Hunter Army Airfield, Ga., according to a Department of Defense release.

The five were identified as: Staff Sgt. Steven P. Blass, 27, of Estherville, Iowa; Chief Warrant Officer Bryan J. Henderson, 27, of Franklin, La.; Capt. Sara M. Knutson, 27, of Eldersburg, Md.; Staff Sgt. Marc A. Scialdo, 31, of Naples, Fla.; and Spc. Zachary L. Shannon, 21, of Dunedin, Fla.

Two other U.S. troops were killed in an insider attack in Wardak province Monday, making it the deadliest day of the year for U.S. troops in Afghanistan. The gunman, reportedly wearing an Afghan army or police uniform, was killed on the scene.

Also on Saturday, U.S. Secretary of Defense Chuck Hagel spoke by phone with Afghan President Hamid Karzai “to discuss issues of shared concern,” according to a statement from Pentagon Press Secretary George Little.

Recent anti-American comments by Karzai during and after Hagel’s first visit to Afghanistan last weekend have strained relations and prompted the NATO commander in Afghanistan, U.S. Gen. Joseph Dunford, to issue a confidential warning to his commanders to increase security, according to news reports.

While Hagel was in Afghanistan last weekend, Karzai accused the U.S. of colluding with the Taliban to convince Afghans of the need for continued U.S. presence in the country, which U.S. officials denied.

On Thursday, Karzai said the U.S.-Afghan relationship “is complicated” by ”terrorism, transition of the Bagram detention facility, continued civilian casualties (from Nato operations), and lack of respect for the national sovereignty of Afghanistan,” The Associated Press reported.

The handover of the detention facility was among the issues discussed by Hagel and Karzai on Saturday, according to Little’s statement.

”They agreed to use the next week to conduct intensive work with a view to concluding an agreement that fully recognizes Afghan sovereignty and our mutual interests in security of the Afghan people and our respective forces,” Little’s statement said.

A ceremonial transfer of the prison at Bagram Air Base had been scheduled for last weekend during Hagel’s visit, but was canceled at the last minute because of unspecified differences between the two sides.

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