(CNN) - It will take NATO-led military forces "another 25 to 30 days to secure that which needs to be secured" in Afghanistan's Helmand province, and a further three months after that to be sure insurgents are being kept out of the area, British Maj. Gen. Nick Carter said Thursday.
But Operation Moshtarak has reached "the end of the beginning," he said in a briefing from Afghanistan broadcast by the Pentagon Channel. "The insurgent was entirely dislocated within 24 hours" of the insertion of troops by helicopter, he said.
The Nad Ali district is "broadly secure," he said, but there is still Taliban resistance in Marjah. "It will be some days before we can be completely confident that Marjah is secure," said Carter, the International Security Assistance Force's head of Regional Command South.
Ten civilians were killed on the second day of the operation, he said. Reports at the time said 12 were killed.
There have been five ISAF casualties during the operation, ISAF said in a statement Thursday, without giving further details.
It said later that four ISAF servicemembers died Thursday - two of them in an improvised explosive device strike; another after a separate IED attack; small-arms fire killed the fourth servicemember. It was not immediately clear whether the four were among the five casualties noted earlier. The four deaths bring to 44 the number of Americans killed this year in Afghanistan. In all, 78 coalition forces have died this year.
Carter's comments came against the background of an intensified U.S.-led campaign against insurgents.
Taliban fighters are resisting an allied military push into area they control in Helmand province in the south of Afghanistan.
"They know this is their last stronghold. They're not backing down," CNN's Atia Abawi reported from the battlefield, where she is embedded with U.S. Marines. The crackle of small arms fire and the whoosh of outgoing mortar rounds from the Marines were clearly audible on the line as she described the battle.
"About five minutes ago Taliban started attacking our area," she said shortly before 8 a.m. ET. "The Taliban are not giving up - they seem to be coming out in squads, (but) they know they can't group together in large numbers" because it would make them easier targets. The Taliban seem to include "foreign fighters who will fight to the death," she said.
Across the border in Pakistan, four people were killed and five were wounded Thursday when a drone fired on a suspected militant compound in Pakistan's tribal region, intelligence sources and a local political official told CNN.
The four who were killed were suspected militants, two intelligence officials told CNN. It was not clear whether the wounded were also militants.
The remote-controlled aircraft fired two missiles at the compound, which is in the Danday Darpakhel area of North Waziristan, one of seven districts in the tribal region along the Afghan border, the sources said. They asked not to be identified because they are not authorized to speak to the media.
The U.S. military does not comment on reported attacks by the pilotless aircraft, but the United States is the only country operating in the region known to have the ability to launch missiles from drones.
–CNN's Pam Benson in Washington, journalist Mati Matiullah in Kabul, and journalists Nasir Dawar and Umar Aziz Khan in Islamabad, Pakistan, contributed to this report