Seventy people were killed and over 100 injured when two suicide bombers blew themselves up in a cantonment near Islamabad [Images] on Thursday.

One suicide bomber blew himself up near the main gate of the Pakistan Ordnance Factories at Wah Cantonment, about 50 km from Islamabad, while the second attacker detonated his explosives near another gate of the establishment.

The blasts occurred with 30 seconds of each other, witnesses said. The bombers struck shortly after 2.30 pm, when a shift at the ordnance factories ends. Hundreds of civilian workers of the factories were emerging from the gates at the time of the attack.

No group claimed responsibility for the attack though the Pakistani Taliban [Images] had recently warned that it would carry out suicide attacks if the government did not halt military operations against it in the North West Frontier Province and the tribal areas.

Wah Cantonment, located near the historical town of Taxila, is a high-security army establishment and is home to 14 ordnance factories that employ over 35,000 people. The factories manufacture a wide variety of military equipment, ranging from arms and ammunition to clothing.

TV channels put the death toll at over 50. Officials were quoted by the channels as saying that the toll could rise as many of the injured are in a serious condition.

A large number of ambulances rushed to the site of the blasts to ferry the injured to nearby hospitals.

The army cordoned off the area and prevented journalists from approaching the site of the blasts. The remains of both suicide bombers were taken away by the security agencies.

A high alert was sounded at all sensitive installations across the country by the interior ministry.

There were also reports that several suspects were detained for questioning in connection with the blasts.

This was the second suicide attack since Pervez Musharraf's [Images] resignation as president on Monday.

Over 30 people, most of them Shias, were killed when a suicide bomber struck at a hospital in the north-western city of Dera Ismail Khan on Tuesday. The Taliban claimed responsibility for that attack.

Thursday's attack also marked the first time that two suicide bombers on foot had struck at the same target.

Prime Minister Yousuf Raza Gilani [Images] and ruling Pakistan People's Party chief Asif Ali Zardari condemned the attack in Wah. Gilani directed authorities to make efforts to expose the "hidden hands behind the incident".

In a statement, Zardari described the attack as "despicable and cowardly" and said it "will only strengthen the resolve of the people of Pakistan and the coalition to fight militancy and extremism."

"The people of Pakistan will never bow before the extremists," he added.