Five members of the NATO-led forces in Afghanistan died in a helicopter crash in southern Afghanistan on Monday, NATO coalition authorities said.

All of the fatalities were American. The incident occurred in the Daman district of Kandahar province, U.S. officials told news agencies.

"Initial reporting indicates there was no enemy activity in the area at the time of the incident," the International Security Assistance Force said in a statement.

In central eastern Afghanistan, meanwhile, two U.S. soldiers died on Monday when an individual wearing an Afghan National Security Forces uniform shot at U.S. and Afghan forces, the ISAF said.

Three policemen and two Afghan army officers also died in the shooting at a remote military base in Wardak province, Reuters reported.

Another 10 U.S. soldiers were wounded, the BBC reported, citing the U.S. military. The killer was shot dead at the scene, the report added.

NATO-led missions in Afghanistan were suspended for almost two weeks in September last year due a rise in the so-called “green-on-blue” attacks.

The  "blue" in such attacks refers to allied forces and "green" refers to Afghan forces. The expression is used to indicate insider killings of U.S. and NATO troops in Afghanistan.

The flashpoint Wardak province has been the site of a recent rise in tensions between Afghan authorities and U.S. troops.

In late February, Afghan President Hamid Karzai ordered U.S. special forces to leave the province by the middle of March following allegations that “armed individuals named as U.S. special force[s] stationed in Wardak province engage in harassing, annoying, torturing and even murdering innocent people,” according to a statement by his office.

On Sunday, Karzai accused Washington of colluding with the Taliban to justify its presence in the country.

The White House strongly rejected the allegations, which were made during a visit by new Defense Secretary Chuck Hagel.

"It is their slogan for 2014, scaring us that if the U.S. is not here our people will be eliminated," Karzai was quoted as saying by AFP. The ISAF troops are to begin a long withdrawal after more than a decade of war.

In the past the Taliban have termed Karzai as a U.S. “puppet” and the Afghan government as a “puppet government.”

Karzai has been adamant that his government must be involved in any U.S.-Taliban contacts, although the Islamist militant group had earlier insisted on face-to-face talks with the U.S. rather than with the Afghan government as the Taliban leaders do not recognize the Karzai administration as legitimate.

In February of last year, Karzai had said that “there have been contacts between the U.S. government and the Taliban, there have been contacts between the Afghan government and the Taliban, and there have been some contacts that we have made, all of us together, including the Taliban.”