Suspected chemical attacks killed at least 100 people in Syria’s rebel-held northwestern province of Idlib on Tuesday and left another 400 suffering from respiratory problems, a Syria medical relief group said.

The death toll is likely to rise, according to the Union of Medical Care Organizations, a coalition of international aid agencies that funds hospitals in Syria and which is partly based in Paris.

The group said the village of Khan Sheikhoun to the south of Idlib had initially been hit before strikes on the White Helmets emergency services center in Khan Sheikhoun and the Al-Rahme hospital.

“We have seen more than 40 strikes since 06h30,” it said. “The toll continues to increase as do the strikes in the Idlib region as well as non-chemical attacks in Hama,” the group said.

(Reporting by John Irish; Editing by Adrian Croft)

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Anadolu Agency via Getty Images A wounded child receives medical treatment at Sahra hospital after the Assad regime forces attacked with chlorine gas in the town of Khan Sheikhoun in Idlib, Syria on April 4, 2017.

Anadolu Agency via Getty Images A child gets treatment at a hospital after Assad regime forces attacked with suspected chlorine gas.

Ammar Abdullah / Reuters A civil defence member breathes through an oxygen mask, after what rescue workers described as a suspected gas attack in the town of Khan Sheikhoun in rebel-held Idlib, Syria April 4, 2017.

Anadolu Agency via Getty Images Civil defense members try to reduce the effects of chlorine gas with water as they carry out search and rescue efforts after a gas attack in Syria.

Anadolu Agency via Getty Images A wounded child waits for treatment at a hospital after Assad Regime forces attacked with chlorine gas to the town of Khan Sheikhoun in Idlib, Syria.

Anadolu Agency via Getty Images Children get treatment at a hospital.

Ammar Abdullah / Reuters A man carries the body of a dead child, after what rescue workers described as a suspected gas attack in the town of Khan Sheikhoun in rebel-held Idlib, Syria on April 4, 2017.

Anadolu Agency via Getty Images Bodies of chlorine gas victims are seen after Assad regime forces attacked with chlorine gas.

Handout/Reuters A still image taken from a video posted to a social media website on April 4, 2017, shows people lying on the ground said to be in the town of Khan Sheikhoun, after what rescue workers described as a suspected gas attack in rebel-held Idlib, Syria.