Washington: US forces, in a big push into areas close to Pakistan's lawless North Waziristan, have killed 115 insurgents in four days of intense fighting against Haqqani militants to gain control of a critical corridor and resupply route to key bases in northeastern Afghanistan.

Deploying long-range bombers from as far away as Persian Gulf emirates of Qatar and bases in Kandahar and Bagram, US and NATO forces are using long-range rockets fired from morethan 120 kms away to break-up large groups of Haqqani network, al-Qaeda and Taliban militants, who, intelligence reports say, are concentrated in Kunar province.

The US commanders have described the ongoing operation codenamed "Knife Edge" as a "high-intensity, sensitive" mission to hit the Haqqani network, the New York Times reported in the firsthand account of the battle from Kunar's provincial capital Asadabad.

American military officials said the fighting in the rugged Kunar province near the Afghan-Pak border has been going on since October 15.

NATO officials said the coalition and its Afghan partners had killed at least 115 insurgents in the past week. The forces are involved in a series of multiple operations that will have larger combined impact.

Simultaneously with the push into Kunar, coalition and Afghan forces have launched big operations elsewhere in eastern Afghanistan with sights set on the dreaded Haqqani network, an al-Qaeda linked group that operates from Pakistan.

"We have many F-15s and F-16s to count, almost continuous coverage," the NYT quoted an American field commander as saying.