iraq car bomb
A damaged car is seen after a bombing in the city of Ramadi, west of Baghdad, Nov. 6, 2014. The bombing killed two people and wounded 22 others, the police said. Reuters/Ali al-Mashhadani

(Reuters) - Three suicide car bombs exploded at a border crossing between Iraq and Jordan on Saturday, killing four soldiers, a witness and an Iraqi border police source said, in an attack claimed shortly afterwards by Islamic State.

The Islamic State militant group claimed responsibility for the attack in a video, saying it had targeted a government complex, control point for the border crossing, and army patrol, according to monitoring group SITE.

A Jordanian official said his government had responded by stepping up security measures at the Tureibil crossing, while an Iraqi defense ministry spokesman said Baghdad would investigate the assault.

The Iraqi government announced a new offensive this month to recapture parts of Anbar, Iraq's Sunni Muslim heartland, from Islamic State, but the Sunni militants struck back by attacking Ramadi, the Baiji refinery, and al-Thirthar dam.

(Reporting by Baghdad newsroom, Suleiman al-Khalidi in Amman, Sami Aboudi in Dubai; Writing by Stephen Kalin; Editing by Raissa Kasolowsky)