BAGHDAD (Reuters) - Islamic State militants are massing near the Iraqi town of Qara Tappa, 122 km (73 miles) north of Baghdad, security sources and a local official said, in an apparent bid to broaden their front with Kurdish peshmerga fighters.

The Sunni militants have made a dramatic push through the north to a position near Arbil, capital of the semi-autonomous Kurdish region.

The movement around Qara Tappa suggests they are getting more confident and seeking to grab more territory closer to the capital after stalling in that region.

"The Islamic State is massing its militants near Qara Tappa," said one of the security sources. "It seems they are going to broaden their front with the Kurdish fighters."

Islamic State has also been using tunnels built by Saddam Hussein in the 1990s to secretly move fighters, weapons and supplies from strongholds in western Iraq to towns just south of Baghdad.

The group, made up of Iraqis, other Arabs and foreign fighters has threatened to march on Baghdad, part of its ambition to redraw the map of the Middle East and impose its radical version of Islam.

(Reporting by Raheem Salman, Writing by Michael Georgy; Editing by Janet Lawrence)