AMMAN (Reuters) - The U.S-led coalition on Tuesday denied its warplanes bombed a Syrian border town in the Islamic held eastern province of Deir al-Zor, a day after a war monitor and activists said air strikes there had killed scores of civilians, including children.

The Syrian Observatory for Human Rights said at least 42 people, including 11 children, were killed on Monday when jets believed to belong to the U.S.-led coalition hit the town of Al-Bukamal near the border with Iraq. They struck near a residential area and a mosque, wounding dozens more, the Britain-based monitor said.

In an emailed statement to Reuters, U.S. army spokesman Colonel Ryan Dillon said that coalition warplanes on Sunday and Monday did not hit the town, targeting only oil production facilities run by the militants more than 50 kms outside of it.

“We did not conduct strikes during the time period of alleged civilian casualties,” Dillon said, adding that other unnamed countries had waged strikes on Al-Bukamal on those days.

Islamic State holds most of Deir al-Zor province, apart from an enclave at the center and a nearby air base controlled by Syrian government forces. The province links territory Islamic State militants control in Syria and Iraq.

Syrian activists and former residents in touch with relatives in northern Syria say there has been a noticeable rise in civilian casualties from coalition raids since the escalation of a U.S.-led campaign to oust the militants from their de facto capital of Raqqa.

The United States military has said it makes “extraordinary efforts” to avoid civilian deaths in its air strikes in Syria and Iraq.