Pakistan has sealed off its border with Afghanistan at Chaman point after security forces apprehended two suspected militants while trying to sneak into Kandahar in the neighbouring country, sources said.

All transit passes issued to Pakistanis and Afghan nationals to cross over to Afghanistan have been cancelled, the Daily Times reported on Wednesday, quoting the unnamed sources as saying.

However, there would be no bar on the United Nations staff to move across the border.

Sensitive equipment and close-circuit cameras have also been installed at Chaman point to check the cross-border movement of militants, who might disrupt peace and stability in the Islamic nation, particularly in the North West Frontier Province by carrying out suicide and militant attacks.

The measures came on Tuesday after investigations revealed that the arrested duo from Swat were to meet a 17-member group of Taliban to implement a plan to kill security forces in different areas of NWFP and smuggle in huge cache of explosives, the sources said.

However, the security forces have not yet disclosed the name of the two suspected militants who were held on Monday while trying to sneak into Spin Boldak, the capital of the Pukhtoon-majority Kandahar in Afghanistan.

Meanwhile, sources said that the Interior Ministry had directed the NWFP police to utilise all available resources for protection of troops deployed in the restive Swat Valley to crack down on the militants.

Security has been tightened further in Peshawar, Nowshera, Risalpur and Mardan cantonments and police have been deployed at sensitive installations to avert any untoward incident.