UN Secretary General Ban Ki-Moon
UN Secretary General Ban Ki-MoonReuters

UN Secretary-General Ban Ki-moon on Monday condemned bombings claimed by the Islamic State (ISIS) group in two Syrian coastal cities and voiced concern about the military escalation in and around Damascus.

More than 148 people were killed in the bomb blasts at bus stations, hospitals and a power station in the cities of Jableh and Tartus, two strongholds of President Bashar Al-Assad's regime.

Ban "condemns the terrorist attacks today that claimed the lives of dozens of civilians in the Syrian coastal cities of Jableh and Tartus," said his spokesman Stephane Dujarric in a statement quoted by AFP.

He expressed "great concern" over the escalating military activity in and around Damascus, particularly in Daraya, Aleppo and Idlib and in northern Homs, especially Al-Houla, he added.

14 civilians -- four of them children -- were killed when a barrage of barrel bombs hit the town of Al-Houla and neighboring villages last week, according to the Syrian Observatory for Human Rights.

Barrel bomb attacks are common in Syria. These are crude weapons -- containers packed with explosives and scrap metal that are typically dropped from helicopters.

Their use in Syria's war has come under fierce criticism by rights groups but Syrian President Bashar Al-Assad has repeatedly denied using barrel bombs and has claimed in interviews that no such weaponry exists.

The West, for its part, notes that only the regime has helicopters from which these weapons are dropped.

Ban on Monday renewed his call to all warring factions to spare civilians and said those responsible for such attacks must face justice.

AFP contributed to this report.