NATO has apologised for the deaths of 12 people after two of its rockets missed their targets on the second day of the US-led offensive against the Taliban in southern Afghanistan.

The victims - all members of the same family - died after the rockets struck a house in Marjah in Helmand province.

The commander of the NATO forces involved in the campaign, US General Stanley McChrystal, apologised for the loss of life and said use of the missile would be suspended.

The military offensive, one of NATO's biggest against the Taliban since the Afghan war began in 2001, is the first test of US President Barack Obama's plan to send 30,000 more troops to seize insurgent-held areas ahead of a planned 2011 troop drawdown.

‘There were bombardments in parts of Marjah and as a result 12 Taliban have been killed,’ Dawud Ahmadi, a spokesman for the provincial governor of Helmand said.

Much of the success of the operation in Helmand province depends on whether the new administration wins the trust of the local population and Afghan troops are effective enough to keep the Taliban from returning.

Civilians have already expressed doubts that Afghan troops can keep control of the district if the Taliban are cleared.

At a meeting with government authorities close to Marjah, some 200 villagers urged the regional government to persuade NATO-led troops to remain in Marjah once they secure the area, Mr Ahmadi said.

‘They said that the Afghan forces do not have the ability to keep control of the area,’ he said.

NATO and the Afghan government's credibility rests on limiting civilian casualties, especially since NATO commanders told Marjah residents to stay home during the offensive, which could last weeks.

The offensive has been flagged for weeks to persuade Taliban fighters to leave so the area can be recaptured with minimal damage or loss of civilian life, in the hope that the roughly 100,000 people there will welcome the Afghan administration.