KABUL: A helicopter crashed in southern Afghanistan Saturday, killing one member of the US-led coalition and injuring another in what was the second deadly air crash in the country in a week, Nato officials said.  

The crashes come as US officials are grappling with tough talk from Afghan President Hamid Karzai whose recent anti-American rhetoric has complicated relations at a time when international troops are withdrawing from the war.

Capt Luca Carniel, a spokesman for the coalition, said there was no enemy activity in the area when the helicopter went down, and that the cause of the crash was being investigated.

Officials did not release the type of helicopter that crashed, or the nationalities of the casualties.

The helicopter went down in Daman district, a few kilometers (miles) east of Kandahar, said Javeed Faisal, the spokesman for Kandahar province.

On Monday, a Black Hawk crashed outside Kandahar, killing five US troops. Two more US troops were killed that day by an insider attack, making Monday the deadliest day for US troops so far this year.

In addition to the casualties, US officials are trying to contend with Karzai's remarks that were so anti-American they prompted top Nato commander Gen Joseph Dunford to issue a warning to his commanders by confidential email this week to be on watch for violent blowback, in the form of more insurgent and insider attacks.

When the email was leaked, Karzai's office responded by saying his comments ''were meant to help reform, not destroy the relationship.''

Karzai started the week by accusing the US and the Taliban of colluding on two deadly suicide bombings last weekend in an effort to create instability and give US forces an excuse to stay.

On Thursday, Karzai did not back down or retract his earlier statements, instead saying the US-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.''

Secretary of Defense Chuck Hagel spoke on the phone with Karzai on Saturday to discuss Karzai's concerns, including the detention facility, according to Pentagon press secretary George Little.

''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 said in a statement.

Karzai is pressuring the US to go ahead with the handover of the US-run detention facility next to Bagram Air Field.

The transfer was scheduled for last week, but was called off when Karzai objected to terms of the transfer, including allowing the US to keep its veto power over the release of Afghan detainees the US feels are too dangerous to free.

Karzai said this week that any further delay could harm bilateral relations.

Another issue dividing the US and the Afghan president is Karzai's demand that US special operations forces leave the province of Wardak, next to Kabul, because of complaints the US or Afghans working with them abused local citizens, arresting several.

Karzai had given them a deadline of earlier this week to leave, but agreed to give Dunford more time to craft a solution that maintains security in Wardak, which is used as a gateway by militants to bring bombers and weapons into Kabul.

Several hundred demonstrators angry over the delayed departure chanted ''US special operations forces out!'' as they marched to the Afghan parliament building in Kabul Saturday.

Kabul's deputy police chief Gen Mohammad Daud Amin said the demonstration of roughly 500 Afghans had been peaceful.

The demonstrators are seeking the release of nine local citizens who they believe were detained by the US forces. Banners in the Afghan languages of Pashto and Dari as well as English read, ''I want my father,'' and ''We want our prisoners back from the government, dead or alive.''

''Americans and US special operations forces must leave,'' said protester Abdul Hadi.

US officials have acknowledged that four men were arrested in the province in joint US-Afghan raids, but had no information on the other five alleged detainees. They have denied the allegations of abuse.