BAGHDAD (AP) — Iraqi forces pressed their offensive against the Islamic State group Friday, expecting to reach the outskirts of the militant-held city of Tikrit, a day after the extremists reportedly "bulldozed" a famed archaeological site in the area. In Paris, the head of the U.N.'s cultural agency said the deliberate destruction of cultural heritage — such as the latest rampage at Iraq's archaeological site of Nimrud — amounts to a "war crime." The discovery of the treasures of Nimrud's royal tombs in the 1980s is considered one of the 20th century's most significant archaeological finds.