By Chris Morris
BBC News, Mullaitivu
The troops are pushing the Tigers into a shrinking territory
Heavy monsoon rains were falling as we approached the outskirts of Mullaitivu in a Sri Lankan armoured personnel carrier.
"We had to fight here for one week or so," said Colonel Arun Aryasinghe, as he showed us a huge earthen defence line constructed by the Tamil Tigers. "It was a very hard battle."
Mullaitivu used to be one of the Tigers' most important bases. Now the Sri Lankan flag flies overhead, and government troops are in complete control.
But they have inherited a ghost town, full of broken buildings. Apart from men in uniform, a stray dog wandering through a burnt-out shop was one of the only signs of life.
When the Tamil Tigers were forced out, they took Mullaitivu's civilian population with them into the surrounding jungles.
For almost a year, as Sri Lankan troops have advanced from the south, the story has been the same. They have taken territory, boosted by better weapons and weight of numbers.
But the local population has melted away in front of them.
Why has the army suddenly had such striking military success?
It is partly because they have taken on the Tigers at their own game - guerrilla warfare.
The army has changed tactics - and those tactics have been working
They have deployed small teams of fighters deep in the jungle, and sent out highly manoeuvrable boats to take on the Tigers' fledgling navy.
Now the rebels have their backs to the wall, holding a shrinking but still significant piece of land. Estimates of their remaining strength vary, but they are unlikely to go down without a fight.
Some of the fighting is pretty close to Mullaitivu. The sound of shell fire echoes through the empty streets.
Just to the north is the final stretch of Sri Lankan coastline under rebel control. If - and they will say when - government forces reclaim it, the Tigers will be surrounded and cut off from the sea.
International aid agencies say a quarter-of-a-million civilians are already trapped in the war zone, and hundreds of people have been killed and injured. The International Committee of the Red Cross (ICRC) has spoken of a major humanitarian crisis.
But the man running this war, Sri Lanka's Defence Secretary Gotabaya Rajapaksa, told me that the numbers were exaggerated.
"It's wrong information," he said, "it is all propaganda. I'm not saying the Red Cross is lying but they are exaggerating."
People who have been into rebel-held territory paint a very different picture, of traumatised civilians moving from place to place with little shelter and no security.
There is little sign of life in the town
A United Nations spokesman told me that UN staff had seen dozens of people killed by shell fire.
But with his troops patrolling the streets of Mullaitivu, and other towns which had previously been under rebel control, Gotabaya Rajapaksa is scenting victory.
The defence secretary categorically ruled out the prospect of any kind of ceasefire for humanitarian reasons.
"No ceasefire," he said. "Why should we?
"Every time there is a ceasefire, the LTTE [Tamil Tigers] use that to their own advantage. That's why this war has been dragging on for 30 years."
And his aim now?
"The mission is... eradicating terrorism and destroying the LTTE completely."
But once again - away from the eyes of the world - it is the civilians of northern Sri Lanka who are suffering.