KARACHI, Nov 1: The Special Services Group of the armed forces carried out a 'routine exercise' inside an under-construction housing complex in Gulistan-i-Jauhar, said an army official who also denied arrest of any key suspect of Al Qaeda network or the Taliban.

The official, who did not want to be identified, told reporters on Monday at the Pakistan Housing Scheme near Pehalwan Goth that it was just a routine exercise. "We have neither arrested anyone linked to the Al Qaeda network or South Waziristan, nor have we detained any suspect here," he claimed.

However, a fruit vendor, Abdul Aziz, who stood across the road in front of the main entrance of the housing complex, said that he had seen a big helicopter hovering over the apartments just before sunset. It tried to land thrice and then some people alighted from it and, using ropes, landed onto the rooftop of the apartments.

He said: "I stand here daily and have been noticing movement of some army jeeps for few days."

A 10-year-old boy, Ziaur Rehman, said that he had seen some army commandos getting down from the helicopter to land onto the apartments' rooftop.

A resident of the area said that he did not notice the movement of army personnel and vehicles for the past few days. "I walk here after dinner daily. I heard sound of explosions and saw the movement of armed forces today. It is unusual."

The area residents said that they had not seen such a large helicopter before which shook the walls of their houses as it roared above.

The army official asserted that the SSG had been carrying out the 'routine exercise' every year in Karachi since 1982. "We had carried out the exercise in Clifton and some other places in the city earlier. This time, we have selected this location", he added.

An official of Nespak, a construction company, who identified himself as Nasir, said that the SSG had obtained a written permission from the company for an indefinite custody of the premises. The army official, however, said that Monday was the final day of their exercise and they would leave the premises by Tuesday evening.

Mr Nasir said that the complex was in its final stage of construction. There are 544 apartments in the housing complex and all of them have been sold out. "We will hand over the same to their owners by March next year," he added.

An intelligence official, who requested not to be named, said that the exercise could be aimed at capturing a key element of Al Qaeda network that was supposedly hiding in the densely populated city.