At least eight staff of Doctors Without Borders, an international aid group, went missing after a building in Syria was hit by four rockets on Monday.
The aid group, known as MSF, released a picture of the building after it was hit, on its Twitter account, Xinhua reported.
Meanwhile, the Syrian Observatory for Human Rights, an anti-government activist organisation based in London, said at least nine people were killed in the shelling in Marat al-Numan city in the province of Idlib.
The Observatory, which says it relies on activists on the ground inside Syria for much of its information, said the shelling was the result of Russian airstrikes, a claim that cannot be independently verified.
Russia has been conducting airstrikes on targets inside Syria since last September. Russian officials have repeatedly said they were not targeting civilians, contrary to the claims of the opposition on the ground.
Much of Idlib fell to the rebel group of Jaish al-Fateh, or Conquer Army, late last year. The Al-Qaeda-linked Nusra Front is a main faction of the Jaish al-Fateh.
