NATO forces are inching their way into the Taliban haven of Marjah, while insurgent snipers are providing a persistent opposition to the incoming troops.

Monday marked the third day of the massive NATO offensive designed to flush the Taliban out of their Helmand province stronghold. Some 15,000 U.S., Afghan and British troops are involved in the operation.

NATO troops were fired upon by snipers throughout Monday, limiting their advance to only a half-kilometre. Multiple firefights broke out throughout the day.

CTV's South Asian Bureau Chief, Janis Mackey Frayer, reported that military officials felt the offensive was proceeding as expected.

"Military officials are saying that things, so far, are going somewhat according to plan on the ground," Frayer told Â鶹´«Ã½ Channel on Monday morning.

"Afghan officials are a little more optimistic, they're saying that the Taliban has run away, they're saying that the coalition and Afghan forces are doing a splendid job in securing the area around Marjah so they may ultimately turn it over to an Afghan government with an Afghan security force."

Afghan Brig. Gen. Mohammad Zazai said civilians had pointed out the locations of deadly mines, suggesting that the incoming troops had gained the public's trust.

"Today there is no major movement of the enemy. South of Marjah they are very weak. There has been low resistance. Soon we will have Marjah cleared of enemies," Zazai said at a briefing in Lashkar Gah, the capital of Helmand province.

The well-publicized offensive officially began after NATO had dropped leaflets for weeks and made repeated public appeals for civilians to flee the area before military operations began.

That knowledge likely prompted some insurgent fighters to leave Marjah before NATO troops rolled into the area, said Afghan Interior Minister Hanif Atmar.

The enemy "had ample time to flee. Our intention was known to both our public and the enemy," Atmar said.

Frayer said NATO had two purposes in mind when advertising the coming offensive.

"First of all, it gives civilians the chance to leave, if they feel they want to and it also sends a message to the Taliban that NATO forces are coming," Frayer said.

NATO's long-term goal is to gain control of Marjah, to have Afghan government members take over administration of the area and to install Afghan security forces to keep the peace.

If successful in Marjah, NATO intends to use the same approach in other hot spots in Afghanistan.

"We are likely to see it replicated across southern Afghanistan, so what we're seeing in Marjah now, we are likely to see in Kandahar province in the months to come," Frayer said.

Civilian deaths

But the offensive has had deadly side effects: Twelve civilians died Sunday when their home outside Marjah was hit by a pair of U.S. rockets. NATO said the rockets were fired after insurgents attacked U.S. and Afghan forces.

Six children were among the dead, a NATO military official confirmed Monday, speaking on condition of anonymity to The Associated Press.

NATO has said the rockets missed their target by about 300 metres and Afghan President Hamid Karzai has called for a thorough investigation into the incident.

The rockets were launched from the High Mobility Artillery Rocket System, which U.S. Gen. Stanley McChrystal -- the top NATO commander in Afghanistan -- has immediately banned the use of, pending a thorough review.

McChrystal apologized for the "tragic loss of life" that occurred when the rockets were fired on the home.

Karzai has made a general appeal for "restraint" prior to the launch of the offensive, asking NATO to be cautious of civilian casualties.

With files from The Associated Press