As Iraqi forces inched forward in the battle to retake Tikrit from Islamic State fighters, the U.S.-led coalition continued its air campaign against militants in Syria and Iraq on Monday with 13 airstrikes, focusing largely near Kobani and Fallujah.
Pentagon spokesman Col. Steve Warren said Monday the United State and its partners have carried nearly 2,800 airstrikes since beginning the campaign in August.
Alongside Peshmerga fighters attempting to push back IS militants in northeast Iraq, VOA Kurdish service reporter Dilshad Anwar saw evidence of heavy airstrikes in the Kirkuk area, which U.S. defense officials said was hit twice by the coalition in the last day.
Watch related video of airstikes on Kirkuk, Kurdish Peshmerga forces
But the United States has not joined the week-old offensive by Iraqi forces and Shi'ite militias as they advance on Tikrit, a stronghold between government-controlled Baghdad to the south and the Islamic State-held Mosul to the north.
On the second front of fighting against the Islamic State group, officials said Monday that a German woman was killed in Syria as she fought alongside Kurdish militia members.
Ivana Hoffman, 19, died Saturday in heavy clashes in the country's northeast near the town of Tel Tamr, where Kurdish fighters and local Christian militias have joined forces against encroaching IS militants.
In a separate incident in Syria, activists say U.S.-led coalition airstrikes hit an oil refinery on Sunday, killing 30 people.
The Britain-based Syrian Observatory for Human Rights, which uses a network of sources throughout Syria to track violence there, said the Islamic State group was operating the refinery, and that the dead included both militants and workers.
In Libya, where the Islamic State group made its presence known last month when members claim to have beheaded 21 Egyptian laborers, nine more foreigners have been kidnapped.
Philippine officials on Monday said four of the oil workers who disappeared several days ago are their citizens. The unidentified attackers also abducted nationals of Austria, Bangladesh, the Czech Republic, and Ghana.
The airstrikes include a recent push to respond to the Iraqi government's request to help protect the country's antiquities, which have been targeted for destruction by the militants in recent weeks.
U.N. Secretary-General Ban Ki-moon said in a statement late Sunday he is "outraged" by the destruction of cultural sites, including the UNESCO World Heritage Site at Hatra in northern Iraq.
He called on the international community to help stop such attacks and the illicit trafficking of cultural artifacts.
VOA's Carla Babb contributed to this report.