Gunfire and explosions could be heard as he spoke to an AFP reporter by telephone.
Fared Bakhtawer, head of the provincial council, said several security checkpoints in the city of Farah were overrun by Taliban fighters and that an intense gun battle was ongoing.
The Taliban has not yet confirmed their casualty toll.
The Afghan Military in the North says the Farah city has been fully cleared of the Taliban militants but clearance operations are still being conducted to ensure the remaining insurgents are eliminated.
The Taliban launched a coordinated assault on Farah shortly after midnight, and quickly overran checkpoints at the city's edge.More news: Internet divided over 'Yanny or Laurel' video clip
Taliban fighters stand guard as senior leader of a breakaway faction of the Taliban Mullah Abdul Manan Niazi, not pictured, delivers a speech to his fighters, in Shindand district of Herat province, Afghanistan, May 27, 2016.
"The Afghan National Defense and Security forces supported by USA forces in Afghanistan air power are on the offensive against the Taliban", he added.
"If the security forces can't take control of the whole city by the end of the day, then it will be very hard to take control of the city anytime soon", he said.
However the speed of the attack, which saw large parts of the city including police headquarters and the governor's compound under siege at different times, caused shock among residents.
Satar Hissaini, a tribal elder in Farah, told AFP that although the situation is "very bad", the city was being defended.More news: ESPN Films & Netflix Team Up for Michael Jordan Doc Series
The Taliban stormed the city in the early hours of Tuesday morning and were pushed back early Wednesday, said Salangi.
The insurgents released a statement warning residents to stay inside their homes and "stay calm".
Many radio and television channels in the province have stopped broadcasting, fearing for their employees' lives, according to media watchdog Nai.
It's also an important economic area with the multi-billion-dollar TAPI (Turkmenistan, Afghanistan, Pakistan and India) gas pipeline planned for the region.
The Trump administration's strategy of renewed aggression here, meant to bolster the country's security, has led to a dramatic hike in the number of airstrikes, many aimed at crippling the Taliban's ability to profit from the drug trade.More news: NCIS Star Reveals She Left Series After Allegedly Suffering Multiple Physical Assaults