KABUL (Reuters) - Afghan security forces backed by U.S. advisers and air strikes fought on Monday to drive Taliban fighters out of the flashpoint city of Ghazni, where hundreds of people have been killed or wounded during four days of fighting.

The Taliban attack on Ghazni, a strategic center on the main highway linking the capital Kabul with southern Afghanistan, is a blow to President Ashraf Ghani weeks before a parliamentary election is due and dampens hopes of a start to peace talks.

The insurgents seized control of the districts of Khawaja Omari north of the city and Ajrestan in the west and officials said dozens of Afghan security forces were dead or missing.

Within Ghazni city, there were contradictory claims by both sides and no way of independently verifying them.

Interior Minister Wais Barmak declared the situation had improved by Monday afternoon, with reinforcements pressing the city’s last pocket of Taliban resistance.

But the Taliban said they were in control of most of the city.

Diplomats in Kabul said the government had admitted being taken by surprise by the attack launched on Friday and, after days with minimal public comment from the presidential palace, Ghani announced on Twitter that reinforcements would be sent urgently.

Afghan officials said U.S. special forces units were on the ground helping to coordinate air strikes and ground operations and the U.S. military said its aircraft had launched two dozen air strikes since Friday.

“U.S. advisers are assisting the Afghan forces and U.S. airpower has delivered decisive blows to the Taliban, killing more than 140 since August 10,” said Lt Col Martin O’Donnell, the spokesman for U.S Forces-Afghanistan.

An Afghan security guard walks during a Taliban attack in Ghazni city, Afghanistan August 12, 2018. REUTERS/Stringer

He said the Afghan government controlled Ghazni, Taliban forces were “isolated and disparate” and Highway 1, the main route from Kabul, was open.

“That said, clearing operations are ongoing and sporadic clashes with the Taliban, particularly outside the city, continue,” he said.

The fighting fueled an increasingly fevered political atmosphere ahead of October’s election, as concern grows over potential security threats from the Taliban and other armed groups.

As the battle raged in Ghazni, a suicide bomber in Kabul detonated explosives near the office of the independent election commission, where dozens of protesters had gathered, killing at least one police officer and wounding another, said a security official.

The protesters had turned out in support of a parliamentary candidate disqualified by electoral officials over suspected links with illegal armed groups, as barred lawmakers encourage protests to disrupt the panel’s activities.

DESTRUCTION

News from Ghazni remains patchy and incomplete, with communications hit after fighting destroyed most of the city’s telecoms masts.

But people escaping the city have described widespread destruction and bloodshed and Afghanistan’s largest television station, Tolo News, broadcast shaky phone footage showing fires apparently raging across the blacked-out center.

Details of casualties were also confused.

Barmak said 70 police were killed in the fighting, while a security official earlier said about 100 soldiers and police had died. He said the Taliban had also suffered heavy casualties including about 50 fighters killed by an air strike on Sunday.

The number of civilian casualties was unknown but people fleeing the city have described bodies lying in the streets and aid groups said hospitals were struggling to cope with the wounded.

“Medication at the main hospital is reportedly becoming scarce and people are unable to safely bring casualties for treatment,” Dr. Rik Peeperkorn, the acting U.N. Humanitarian Coordinator for Afghanistan, said in a statement.

The attack on Ghazni, the Taliban’s heaviest blow since they came close to overrunning the western city of Farah in May, has hit hopes of peace spawned by a surprise three-day truce during June’s Eid al-Fitr holiday.

Officials said Taliban fighters in residential areas knocked down walls to ease movement and make the security forces’ task of targeting them harder.

“The militants know our forces will not attack civilians, so they are using young men as human shields to walk around the city and set buildings on fire,” said one official in Kabul.