Kabul: A knife-wielding Afghan man has been arrested after he broke an emergency window mid-flight on an Ariana Afghan Airlines passenger plane, but the motives behind the incident were unclear, the Interior Ministry said yesterday.

The incident happened on Sunday on an Ariana plane flying from Kabul to the Iranian city of Mashad via the southern Afghan city of Kandahar.

The man was subdued and was being questioned in Kandahar by security officials, the ministry said.

"One of the passengers had a knife and while the plane was flying mid-flight he wanted to commit a destructive action on the plane," Interior Ministry spokesman Zemarai Bashary said.

"But before that could happen, security personnel and passengers inside the plane identified the passenger and arrested this suspect ... we're questioning the man to find out what was his motive."

Lutfullah Tasleem, deputy head for Ariana Airlines, said the passenger stood up from his seat and kicked a round window next to it.

Motive not known

"We do not know the motive of the person and do not know if he was mentally disordered or not," Tasleem said.

While there was no confirmation the incident was linked to any militant attack, the arrest comes as the Taliban announced an offensive, Afghan government officials and diplomats said on Monday.

Thousands of western and Afghan troops are gearing up to launch a military campaign against the Taliban in their spiritual stronghold in Kandahar next month.

"We have 72 hours to question him and we will soon let you know for what reason he wanted to do this, whether this [was] a hijack or another destructive plan to bring the plane down," the official said.

The man was from a northern province of Afghanistan.

In 2000, an Ariana plane was hijacked in Kabul and flown to London where the siege ended peacefully after four days. That hijack was linked to a group of Afghans claiming asylum.