Security stepped up as Iraq heads towards crucial vote

US and Iraqi forces stepped up security across Iraq today and prepared to impose an overnight curfew in an effort to reduce insurgent attacks aimed at wrecking this weekend’s constitutional referendum.

One day after Iraqi politicians approved a set of last-minute amendments to the constitution without a vote, sealing a compromise designed to win minority Sunni Arab support for the charter, cities such as Baghdad were unusually quiet as a four-day national holiday began, closing government offices and schools ahead of Saturday’s vote.