US Steps Up Syria Bombing Against ISIS

The U.S. stepped up airstrikes in northeastern Syria against Islamic State targets Sunday while suicide bombings blamed on the terror group in western Syria killed more than 100.

At least 50 were killed and more than 200 were wounded Sunday in a series of blasts at a vegetable market in the Damascus suburbs, according to Syrian state television. In the central city of Homs, two suicide car bombings killed at least 57, the Syrian Observatory for Human Rights monitoring group said.

The ISIS attacks came as Secretary of State John Kerry sought to revive talks on a "cessation of hostilities," whose initial deadline last Friday came and went while fighting continued on several fronts amid Russian airstrikes.

Kerry, who was in Jordan, told reporters he spoke again with Russian Foreign Minister Sergei Lavrov on a temporary halt to hostilities. President Obama was also expected to be in contact with Russian President Vladimir Putin this week, Kerry said.

"I do believe that in the next few days, during which time we try to bring this into effect, there is somehow going to be a tipping point," Kerry said of the prospects for a limited ceasefire in the Syrian civil war that the United Nations estimates has killed more than 250,000 and displaced millions.

"A cease-fire requires an understanding of obligations. You have to be specific about who is doing what, about what is required of each," Kerry said. "We are very clear that if you don't choose to be part of it, then you are choosing to perhaps make yourself a target."

Kerry said relief columns had managed to reach several areas outside of Damascus but continued fighting in other areas had blocked efforts by the U.N.'s World Food Program and humanitarian groups to truck in aid. The U.S. has thus far ruled out airdrops to areas where the U.N. said civilians were at risk of starvation.

In northeastern Syria, the U.S. carried out 18 airstrikes Sunday against ISIS targets and in support of offensives by the U.S.-backed and mostly-Kurdish Syrian Democratic Forces, according to Combined Joint Task Force (CJTF)-Operation Inherent resolve led by Army Gen. Sean MacFarland.

Previous reports by CJTF said that the U.S. conducted nine airstrikes in Syria on Feb. 20 and also nine on Feb. 19. The U.S. has maintained that strikes against ISIS in Syria will continue no matter the outcome of the negotiations on a cessation of hostilities.

Nine of the 18 latest airstrikes focused on ISIS targets in Hasakah governate in northeastern Syria. The SDF last Friday claimed to have routed ISIS fighters from the city of Shadadi, the last ISIS foothold in the Hasakah area bordering Iraq. Shadadi includes hundreds of oil and gas wells, a major source of ISIS funding.

In a video briefing to the Pentagon last Thursday, Air Force Lt. Gen. Charles Q. Brown Jr., commander of U.S. Air Forces Central Command, said that his command currently was reviewing allegations that U.S. airstrikes in Hasakah last week may have killed 38 civilians.

"I have been made aware of the potential civilian casualties that have happened at Hasakah," Brown said. "And like we do for every potential civilian casualty, we go through an assessment -- to assess the credibility" of the allegations. "We'll go through an assessment process and eventually an investigation if required," he said.

-- Richard Sisk can be reached at richard.sisk@military.com.

Related video: