The internationally recognised Libyan Government of National Accord (GNA) has condemned air strikes launched by forces loyal to retired Major General Khalifa Haftar on the capital Tripoli saying they are "tantamount to war crimes".
"These criminal and terrorist acts will not pass without a severe response on the battlefields," the GNA said in a statement.
At least five children were killed and ten others wounded when an air strike targeted a residential area in Tripoli on Sunday.
GNA spokesman Mohamed Gnounou said nine children and two women, one of whom was pregnant, had been killed in a separate attack launched by an Emirati drone. The UAE backs Haftar in the Libya unrest.
"The absence of a firm and deterrent international stance towards the war criminal [Haftar] has encouraged him to continue committing these heinous violations that are tantamount to war crimes," the statement said.
"The competent authorities of the GNA are documenting these crimes and coordinating with international human rights organisations to bring the perpetrators to justice," it added.
Since 4 April, Haftar's forces have launched an offensive against the capital, Tripoli, in an attempt to capture it from the GNA.