Pakistan Foreign Ministry Spokesman Moazzan Khan said Monday the release of the prisoners was done "to help the peace process in Afghanistan."

One of the four prisoners released was former Taliban Justice Minister Mullah Nooruddin Turabi, whom Afghan Taliban field commanders have said was the former "right-hand man" of the movement's leader, Mullah Mohammad Omar.

Afghanistan has been pressuring Pakistan in talks (pictured above) to release prisoners that could help bring the two countries together. Afghan officials have said that senior Taliban leaders in Pakistan could help bring militants to the negotiating table.

It remains unclear what role the four released prisoners could play in the peace process. Pakistan released nine Afghan Taliban members last month, officials said.

In follow-up talks between the two countries, Pakistan agreed to release more Taliban prisoners to facilitate efforts to end the 11-year war between the Taliban and the Afghan government.

Still in Pakistani custody is former Taliban second-in-command Mullah Abdul Ghani Baradar. Officials in Pakastan said they would consider releasing him. Baradar was captured in 2010.

The Taliban took control of Afghanistan in 1996, but were ousted in 2001 by US-backed forces. Many in the country are concerned the group could again seize power after the US and NATO military withdrawal from the country, scheduled for 2014.

dr/jm (Reuters, AFP, AP, dapd)