Clashes on the Afghan-Pakistani borders have continued for the past three days, with both countries claiming they inflicted heavy losses on the other side.

On Sunday, the Pakistani military said it had killed more than 50 Afghan soldiers since the fighting erupted Friday at the Chaman border crossing, which divides Pakistan's southwest Baluchistan province and Afghanistan's southern Kandahar province.

Gunfire and artillery shells have killed scores of civilians as well, and hundreds of villagers have fled to safer areas.

Worst fighting in years

On Friday, Pakistani troops were accompanying census workers in the border area when the fighting started. Afghan police spokesman Zia Durani accused Islamabad of using the census as cover for "malicious activities and to provoke villagers against the government."

Durani also claimed Pakistani "militias" were trying to cross the border.

In turn, the Pakistani military said Afghanistan border guards were creating "hurdles" for census-taking "despite the fact that Afghan authorities had been informed well in advance" of the process. The army closed the Chaman border crossing, which is one of the two main transfer points on the border, after the exchange of fire. 

"We are not pleased to tell you that five Afghan check posts were completely destroyed - more than 50 of their soldiers were killed and over 100 were wounded," Major General Nadim Ahmad, head of Pakistan's paramilitary Frontier Corps, told reporters on Sunday.

"We are not happy for their losses but we were forced to retaliate," he said, adding that two Pakistani soldiers were killed and nine wounded in the incident.

Kabul quickly denied the claim. "A very false claims [sic] by a Pakistani Frontier Corp that as many as 50 Afghan soldier [sic] lost their lives in Pak retaliation; totally rejected," tweeted Sediq Sediqqi, a government spokesman.

Samim Khpalwak, a spokesman for the governor of Kandahar province, instead said two troops were lost in the attack, in addition to one civilian death.

Mutual suspicion

While the border clashes between Afghanistan and Pakistan are not a new occurrence, observers say this time around the situation is more "warlike."

"There have been at least two mass protest rallies in Kandahar and Torkham against Pakistan's alleged provocation and meddling in Afghan affairs," said Shadi Khan Saif, DW's correspondent in Kabul.

Ties between Afghanistan and Pakistan have deteriorated in the past few months, with Kabul becoming increasingly wary of Islamabad's alleged support for Islamist militants. Both countries accuse each other of providing jihadists with safe zones to launch attacks across the border.

A number of high-ranking Pakistani officials have visited Kabul in the past few weeks to allay the Afghan government's concerns, but the visits have not yielded positive results. Afghan President Ashraf Ghani reportedly turned down a recent Pakistani invitation to visit Islamabad.

Experts say the main reason behind an increasing hostility between the two countries is Kabul's growing ties with Pakistan's archrival India. In the past few years, Afghanistan has drifted closer to India, whereas Pakistan is seeking to forge closer ties with China and Russia to counter New Delhi's growing influence in Kabul.

India and Afghanistan have been extremely critical of Pakistan's role in Afghanistan. They accuse the Pakistani military and spy agencies of backing Taliban insurgents and destabilizing Afghanistan so that Islamabad can have an upper hand in geopolitics.

Controversial border

Amid worsening ties with Afghanistan, Pakistan announced in March it had started building a fence along the volatile Afghan-Pakistani border. Islamabad said the move was aimed at restricting the movement of Islamist militants that cross over the porous border and launch attacks on Pakistani soil.

The move, however, is extremely controversial in Afghanistan and among the Pashtu-speaking people who live on both sides of the border.

Every day, thousands of Afghans and Pakistanis cross the Durand Line - the 2,430-kilometer (1,510 miles) boundary established by the British during their colonial rule. The Afghan government does not recognize the Durand Line as the official border between Afghanistan and Pakistan, nor do many Pashtuns who share historical, cultural and family ties.

The Pashtuns can easily travel back and forth across the border, but the deteriorating political ties between the two countries are now causing them problems.

Pakistan's move to fence the crossings is purportedly aimed at stopping militants from Afghanistan from entering the country. Experts, however, say the measure is futile because militants don't necessarily have to use the official crossings. Instead, militants with sanctuaries on either side of the border often use one of many other unofficial crossings along the frontier.

"There are over 20 unofficial crossings along the Afghan-Pakistani border which militants use to move between the two countries," Wahid Muzhdah, a Kabul-based analyst on the Taliban and a former member of the group, told DW.

Every time Islamabad is criticized by the international community or angered by close ties between its archrival India and Afghanistan, it closes the border to pile pressure on the Afghan government, says Faizullah Zaland, a lecturer at Kabul University.

Beneficial for jihadis

Against this backdrop, analysts say the latest clashes and border closing will not provide solutions to the issues the neighboring countries have with one another; rather, they will only embolden extremists in the area.

"Security incidents in Pakistan have increased in recent months. If clashes between the two countries continue, extremists on both sides of the border will only get stronger and pose an even greater threat to the region," said Pakistani journalist Shahid Shamim.

He believes the only way out of the current problem is for the countries to pursue diplomacy and work together to ensure the safety of the local residents.