KANDAHAR, Afghanistan (Reuters) - Afghan security forces have been battling to push back Taliban fighters seeking to cut off the capital of the southern province of Uruzgan, officials said on Sunday as army units worked to clear roadside bombs from the main highway into the town.

An Afghan National Army (ANA) soldier keeps watch during a patrol in Dand Ghori district of Baghlan province, Afghanistan March 15, 2016. REUTERS/Omar Sobhani - RTSAIBW

The insurgents have in the past month stepped up their offensive aimed at taking control of Uruzgan, which straddles one of Afghanistan’s main opium and gun-smuggling routes. NATO commanders view the rural province as a key battleground as, if it fell, the Taliban could use it as a springboard to launch attacks on Helmand and Kandahar further to the south.

The Taliban is seeking to isolate the provincial capital Tarin Kowt from outlying districts and over the past week has been fighting Afghan forces for control of the road between the town and Shawali Kot in Kandahar province.

The battle has added to the pressure on stretched security forces engaged in heavy fighting from Helmand in the south to Kunduz in the far north.

A spokesman for the Afghan army’s 205th Corps said troops had reopened the route but the situation was still unstable and the road was threatened by improvised explosive devices (IEDs) planted by the insurgents.

“We launched a counter-attack that inflicted heavy casualties to the Taliban and reopened to the highway but it is heavily mined and our engineers are working to clear IEDs off the road,” army spokesman Mohammad Mohsen Sultani said.

Underlining the extent of the threat, General Abdul Raziq, the Kandahar police chief who gained a fearsome reputation fighting the insurgents in his home province, has joined the battle, according to Zia Durani, a spokesman for the head of Uruzgan’s provincial police.

Brigadier General Charles Cleveland, spokesman for the NATO-led Resolute Support mission in Kabul, said the situation in the province was “serious” although there did not appear to be any immediate prospect of Taliban victory.

“We’re watching it closely and there is concern about Uruzgan,” he said. “We don’t think either the province of Uruzgan or the provincial capital Tarin Kowt is about to fall but we’re watching it closely,” he said.

‘TALIBAN ARE EVERYWHERE’

Uruzgan neighbors the Taliban heartlands of Helmand and Kandahar and is among the least-developed areas of Afghanistan, with only 8 percent of the population having access to electricity. Its mix of flat and mountainous terrain has been fertile ground for insurgents who fought Australian, Dutch and U.S. troops for years.

So far no additional foreign troops have been sent to bolster the defense, as they were in Helmand earlier this year, and coalition aircraft have not carried out air strikes in support of Afghan troops fighting the Taliban, Cleveland said.

But the fighting in Uruzgan underlines how difficult ensuring security in remote areas has been for the Western-backed government in Kabul, which is estimated to control only about two-thirds of the country.

“The Taliban have not been defeated. They are everywhere,” said provincial council chief Abdul Karim Khademzai. “Apart from one district, all roads from the district centers to the provincial capital have been cut off and the government only control the provincial capital,” he said.

The districts of Deh Rawod, to the west of Tarin Kowt and Khas Oruzgan, to the east, have long been targeted by the insurgents, who say they have control of large parts of the province and now threaten Tarin Kowt.

“If the provincial center is captured and liberated, it will inevitably be a huge blow for the enemy as they will lose their only toehold in the province,” Mullah Aminullah Yousuf, identified on the Taliban’s website as the insurgent official in charge of Uruzgan province, said in an interview on the site.

With the annual opium harvest now in full swing, Taliban tax collectors have been raising funds from local farmers, who depend heavily on the crop but as fighting has intensified, life has become increasingly difficult, said Amanullah Hotaki, a local tribal elder.

“In some districts where the Taliban are in control, food prices have gone up, there are no hospitals, people die on the way to Kandahar to get treatment,” he said.