A suicide bomber¹ has attacked an army facility in Pakistan's troubled north-west, killing² at least 20 soldiers and injuring others, officials say.

巴基斯坦官员称，一个人体炸弹袭击了动乱的西北部地区的一座军事设施，杀死至少20名士兵并使多人受伤。

Police described the bomber, who struck in the city of Mardan, as a male teenager dressed in school uniform.

He attacked as recruits（新兵） conducted morning exercises.

There had been a relative lull³（间歇，暂停） in attacks on the army in the region, where Taliban militants⁴ are active, correspondents say.

Prime Minister Yusuf Raza Gilani condemned⁵ the attack on the Punjab Regiment⁶ Centre.

"Such cowardly attacks cannot affect the morale⁷（士气，斗志） of the security agencies and the resolve of the nation to eradicate⁸（根除，灭绝） terrorism," he said in a statement.

Previous attack

Mardan police official Abdullah Khan told the BBC that the teenage bomber had been wearing the uniform of a school located in the area, Aziz Bhatti College.

The bomber struck at 0800 (0300 GMT) as recruits were doing physical training on the parade ground, he said.

A bomb attack on the same centre in 2006 killed at least 20 soldiers.

The Punjab Regiment is one of Pakistan's most famous military units.