An al Qaeda operative from Yemen who was arrested by the Pakistani forces in Karachi on Tuesday is reported to have spilled beans about the network's movements and future plans.

The man was identified as Abu Sohaib al Makki, alias, Muhammad Ali Qasim Yaqub and it was said that he has been working along the Pakistan-Afghan border under al Qaeda leaders.

The U.S. Embassy in Islamabad said it was not familiar with his name and he does not appear on any lists under the U.S. rewards for justice program as reported in Reuters.

The arrest of al Makki is a major development in unraveling the al Qaeda network operating in the region, the Pakistani military said in a statement.

It was announced a day after U.S. senator John Kerry warned Pakistani leaders that Congress was asking tough questions about aid to Islamabad after al Qaeda leader Osama bin Laden was killed on Pakistani soil.

The military has not given details on al Makki's rank in al Qaeda or when he was arrested.

He has given information about movements of some other people, said a senior official, referring to militants. We are evaluating the information and planning some action.

Military sources added that al Makki came to Pakistan in 2001 and operated in the border area between Pakistan and Afghanistan.

He was hiding in a house right in the middle of the city,” a senior security official said.

The arrest was made after intelligence operations started in various cities after the May 2 shootout.

The Pakistani intelligence is still facing pressure to explain how bin Laden appeared to have spent years in Pakistan, close to the intelligence headquarters.

The arrest has been made a day after gunmen on motorcycles shot dead a Saudi diplomat in Karachi as he drove to work.