Pakistani forces detained 12 Iranian Revolutionary Guards Monday for crossing into Pakistan days after an Iranian commander was reported saying his men should be allowed to confront terrorists in Pakistan. The Guards were arrested in the Mashkhel area on the border with Iran eight days after a suicide bomber killed 42 people, including six Revolutionary Guard commanders, in Iran's southeastern Sistan-Balochistan province. On Tuesday last week, a senior Revolutionary Guards commander said his force should be given permission to confront terrorists inside Pakistan, state media reported. “It's a serious matter. We are investigating why they crossed into our territory,” said a Pakistani border security official. Another Pakistani security official said Iranian border officials had told them that the encroachment was accidental and happened after the Guards launched an operation against Jundallah militants near the border.