An Afghan court became a battleground on Wednesday when five militants stormed the building where Taliban insurgents were standing trial.<br/> <br />Officials say at least seven people were killed and over 70 injured in the attack in the province of Farah, near the Iranian border.<br/> <br />One of the attackers blew himself up, while a gun battle ensued between Afghan security forces and other militants.<br/> <br />The Taliban claimed responsibility for the attack in a text message sent to the media, adding that the insurgents standing trial had been freed.<br/> <br />The incident adds to concerns over how Afghan security forces will managed once NATO-led combat troops withdraw at the end of next year.