Kandahar, Afghanistan ? A top Taliban commander said Wednesday the group has 4,000 fighters bracing to rebuff NATO’s largest-ever offensive in southern Afghanistan, now in its second day.

Suicide bombers are ready, land mines have been planted and helicopters will be targeted, Mullah Abdul Qassim, a top Taliban commander told The Associated Press.

NATO, meanwhile, announced the capture of a senior Taliban fighter who had eluded authorities by wearing a woman’s burqa. Mullah Mahmood, who is accused of helping Taliban fighters rig suicide bomb attacks, was seized by Afghan soldiers at a checkpoint near Kandahar, the alliance said.

Speaking by satellite telephone from an undisclosed location, Qassim said the Taliban has 8,000 to 9,000 fighters in southern Helmand province, including some 4,000 in the northern part of that area where NATO launched its largest-ever offensive. He said all the fighters were Afghan, denying reports of foreign fighters in the region.

“All of them are well-equipped and we have the weapons to target helicopters,” Qassim said. “The Taliban are able to fight for 15 or 20 years against NATO and the Americans.”

New mines have been planted, and suicide bombers are ready to attack, said Qassim, whose voice was recognized by an AP reporter who has spoken with him before.

Operation Achilles, comprising some 4,500 NATO and 1,000 Afghan troops, is focused on securing lawless regions of northern Helmand – the world’s biggest poppy-growing region.

The offensive follows a mission last fall that wiped out hundreds of militants who fought in formation in neighboring Kandahar province, prompting NATO spokesman Col. Tom Collins to say this week the military would welcome a repeat of those tactics.