Taliban fighters have killed at least six policemen in an attack on a checkpoint and kidnapped dozens of bus passengers in two separate incidents in southern Afghanistan, officials said.

A group of fighters wearing army uniforms kidnapped 30 people, including 19 policemen, after stopping a bus on Tuesday night at the border between Kandahar and Uruzgan provinces.

"There were civilians in the bus as well and we are trying to identify the people kidnapped in the attack," Qudratullah Khushbakht, a spokesman for the Kandahar governor, told Al Jazeera.

{articleGUID}

In the second incident, a police checkpoint in the Shah Wali Kot district of Kandahar province came under attack by the Taliban fighters leaving six policemen dead and wounding five others, General Abdul Razik, Kandahar's police chief, told local media.

The Taliban claimed responsibility for both attacks saying they kidnapped police officers "alive".

The Afghan army and the US-led coalition forces continue to battle the Taliban for the control of areas in the country but the security situation has been deteriorating.

Rising casualty

According to a report published in 2017 by the Special Inspector General for Afghanistan (SIGAR), a US congressional watchdog, a total of 2,531 Afghan security forces were killed and 4,238 wounded in the first four months of the year.

In an earlier report by SIGAR, at least 6,785 Afghan soldiers and police personnel were killed in the first 10 months of 2016, showing at least 20 soldiers and police being killed each day highlighting challenges faced by the Afghan army.

According to a recent survey by the BBC news network, the Taliban are active in 70 percent of Afghanistan's districts, fully controlling four percent of the country and demonstrating an open physical presence in another 66 percent.

On Wednesday, Afghan President Ashraf Ghani offered to recognise the Taliban as a legitimate political group, as part of a proposed process he said could lead to talks aimed at ending more than 16 years of war.

Earlier, the armed group said that they wanted direct talks with America.

A senior Taliban official based in Doha told Al Jazeera on Tuesday that the group invites US officials to its political office in Qatar to discuss a "peaceful solution" to end the bloodshed in Afghanistan.

The Taliban official also said that departure of American troops from Afghanistan remains a precondition for the group's talks offer.