Syrian government air strikes overnight put four hospitals in Aleppo province out of action, the British-based Syrian Observatory for Human Rights has said.
The bombardment killed a two-day-old baby in the children's hospital in a besieged eastern neighbourhood of Aleppo, said the Independent Doctors' Association, a group of Syrian doctors that supports clinics in the city.
The infant's oxygen supply was cut after a strike on the hospital last night, the second strike on the hospital in about nine hours, according to the group.
"The doctors could only yell for their colleagues to take cover and shield the babies," the group said in a statement.
The doctors said the four hospitals that were hit - the children's hospital, Al-Bayan, Al-Zahraa, and Al-Daqaq - would all be going out of service "as a result of the escalating series of aerial attacks taking place against health facilities in Aleppo by Syrian and Russian warplanes".
The World Health Organisation said Syria was the most dangerous place for health care workers to operate last year, with 135 attacks on health facilities and workers in 2015.
In recent months, several hospitals have been damaged and medical staff killed in the densely populated eastern neighbourhoods of Aleppo city.
A hospital in the eastern Maadi neighbourhood was hit just eight days ago, wounding some of the staff and patients inside.
More than 280,000 people have been killed since Syria's conflict erupted in 2011, and millions have been forced to flee.
Meanwhile, Syria's government has said it is ready for further peace talks with the opposition and that it was intent on a political solution to the five-year conflict.
"Syria ... is ready to continue the Syrian-Syrian dialogue without any preconditions ... and without foreign interference, with the support of the United Nations," state news agency SANA quoted an official in the foreign ministry as saying.
The UN hopes to convene a new round of intra-Syrian peace talks in Geneva in August.
Previous rounds of talks this year broke down as fighting escalated, particularly around Aleppo, where government forces recently cut off the only road into rebel-held areas of the divided northern city.
