Peshawar, Feb 10 (IANS): At least 27 cadets were killed and 40 were injured Thursday in a suicide blast carried out by a teenager disguised as a schoolboy at a military training centre in northwest Pakistan, said officials.

The suicide attack targeted the Punjab Regiment Center in Mardan in Khyber Pakhtunkhwa province, said police official Zeeshan Haider.

Mardan is about 50 km northeast of Peshawar.

"The blast was carried out by a teenaged boy who entered the premises in a school uniform and blew himself up," said a security official.

"The cadets were going through their routine exercise at that time in the Punjab Regiment Center of Pakistan Army," the official said.

The injured and the dead were taken to Combined Military Hospital (CMH). The training center has been targeted by militants twice during the last couple of years but Thursday's blast was the deadliest.

Khyber Pakhtunkhwa Minister Bashir Bilour visited the blast site and said: "Our province has become a war zone and we request the federal government as well as the global powers to pay immediate attention to the burning situation."

Banned militant outfit Tehreek-i-Taliban has claimed responsibility for the attack. Taliban have also been masterminding most deadly terrorist attacks in Pakistan's urban areas and against security forces earlier as well.

The province and northwestern tribal areas, bordering Afghanistan, have become a battleground ever since the country's security forces launched a crackdown against Taliban and Al-Qaeda militants in 2007.

All those killed and injured were army men, DPA quoted Muhammad Adil, the top civilian administrator in Mardan, as saying.

A Pakistani military spokesman, Major General Athar Abbas, said this week that 2,700 troops and 300 intelligence agents have been killed in such attacks since 2003.