Fighting with Taliban flares in the west, and east, of Afghanistan

The clashes, described as the worst since 2001, have intensified concerns about a resurgent Taliban.

Intensified fighting in two parts of Afghanistan in the past few days is being described in press reports as the most serious in those locations since the US-led invasion of that country in 2001, and raising concerns about a resurgent Taliban movement.

Agence France-Presse reports on fighting in the western Gulistan district in the past three days as NATO and Afghan government troops have sought to "retake" the area from the Taliban.

An operation by local and NATO troops to retake a district in the increasingly troubled Farah province from the hardline rebels entered its third day, provincial police spokesman Mohammad Gul Sarjang said.

On Wednesday Afghan police said up to 40 Taliban militants were killed and 20 wounded. Taliban militants have taken over several districts in Afghanistan for brief periods of time but have kept control of only one, Musa Qala district in southern Helmand province, which they captured almost a year ago.

Helmand, Afghanistan's biggest opium growing region, borders Farah and hundreds of militants from the province crossed over into Gulistan district during the current bout of fighting.

The New York Times, citing Canadian and Afghan officials, says that for the first time since 2001, Taliban fighters have moved in force just north of the city of Kandahar, once a Taliban stronghold, sparking fierce fighting with Canadian-led forces in the area. The paper also notes that the death of a powerful pro-government warlord in the area has enabled the Taliban offensive, underscoring the fragility of security efforts there.

Control of the area, known as the Arghandab district, would allow the Taliban to directly threaten Kandahar, southern Afghanistan's largest city.

Sarah Chayes, an American journalist and aid worker who has lived in Kandahar since 2001, said a powerful pro-government leader in the district, Mullah

Naqibullah, died of a heart attack two weeks ago. Over the last several years, Mullah Naqibullah survived multiple attempts by the Taliban to kill him, shesaid, and was "the bulwark" that blocked the hard-line Islamic group from entering Kandahar from the north.

But in a sign of the weakness of President Hamid Karzai's government in the area, joyous Taliban fighters seized control of Mullah Naqibullah's home village in Arghandab within two weeks of his death.

The Associated Press reports that two Afghan children died in fighting overnight in Nangarhar Province, as US and Afghan forces raided a suspected militant safe house.

The latest civilian casualties came as U.S. and Afghan troops were raiding a compound suspected of harboring militants belonging to a suicide bombing network.

"It is regrettable that the civilian lives were put in danger by the militants and our sincere condolences goes to the families of the deceased and wounded," said (US-led coalition spokesman Maj. Chris) Belcher, noting the military has launched an investigation.

Violence in Afghanistan this year is the deadliest since the 2001 U.S.-led invasion that toppled the Taliban militant movement from power in the country.

More than 5,600 people have died this year due to insurgency-related violence, according to an Associated Press count based on figures from Afghan and Western officials.

The British Broadcasting Corp. reports heavy casualties in the Kandahar fighting.

Fifty Taleban have been killed, according to Afghan police, and 40 injured, although those figures are impossible to confirm independently. The police also said one Afghan soldier and three police officers were killed.

Correspondents say that fighting in Afghanistan is the heaviest since the fall of the Taleban six years ago, and civilians are increasingly among the casualties.

On Monday Nato denied claims by an official in the province of Wardak that 13 Afghan civilians were killed in a Nato air strike near Kabul.

In an opinion piece in the International Herald Tribune Roger Cohen recounts a recent trip to Afghanistan, which convinced him that the US will need to make a long-term military commitment to the country if stability is to be achieved.

I heard many assessments of how long Afghanistan will depend on Western military assistance, but Abdul Jabar Sabet, the attorney general, was bluntest: "The Afghan army will not be able to defend the country for 10 years, so the international force has to be here for at least a decade."

The next U.S. president will face an enduring challenge in Afghanistan of immense proportions. He or she will need to level with the American people, in a way President George W. Bush never has, about the real burden of an attempt to build two countries from the ground up at once.

One reason Afghanistan is so challenging is that while it's a desperately poor country, the country's booming opium and heroin trade provides ready funds for insurgents. The United Nations said Wednesday that most of the profits from the drug trade go to terrorists and criminals, and calls Afghan opium exports a "tsunami."

Afghanistan had a record harvest of 8,200 tons of opium in 2007, a 34% increase in production over 2006. The total opium export is valued at $4 billion in Afghanistan, an increase of 29% over 2006. The opium economy is now equivalent to more than half (53%) of the country's licit gross domestic product.

This deadly export gains value at every border crossing, because of the risks associated with smuggling. By the time the heroin hits the streets of Moscow, London or Paris, the Afghan opium export could be worth up to 100 times more. For Antonio Maria Costa, executive head of the UN Office on Drugs and Crime, "while opium brings some revenue to Afghanistan, over 90 per cent of profits are made by international criminal gangs and terrorists networks".

Meanwhile, Japan said its Navy will stop supporting NATO forces in Afghanistan, The Guardian reports.

Japan's government has ordered its navy to end its mission in support of coalition forces in Afghanistan after failing to win opposition backing to renew the deployment before today's midnight deadline ... Opposition parties, which gained control of the upper house of Japan's parliament in July, said the mission did not have a UN mandate and possibly violated the country's pacifist constitution, which severely limits the military's overseas role.

The prime minister, Yasuko Fukuda, today vowed to pass new legislation that would enable Japan to play a smaller, but symbolically important part in the US-led war on terror.