The number of Russia-led forces attacks in Donbas, eastern Ukraine, on Saturday, July 13, more than doubled overnight since an evening update by the Ukrainian Joint Forces Operation (JFO) Headquarters on Saturday.

"On July 13, armed formations of the Russian Federation violated the ceasefire 15 times," the JFO HQ said on Facebook in a morning update on Sunday, July 14. "In four instances, they used 122mm artillery systems along with 120mm and 82mm mortars, which are banned under the Minsk agreements."

Read alsoDonbas warzone update: Two Ukrainian soldiers wounded amid six enemy attacks July 13

It reported about six enemy attacks in the evening update on Saturday.

The enemy also opened fire from grenade launchers of various systems, large-caliber machine guns, and rifles.

Under attack were the villages of Shyrokyne, Opytne, Vodiane, Novotroitske, Verkhniotoretske, Pisky, Zaitseve, Novo-Oleksandrivka, Novoluhanske, and Krymske, and the town of Avdiyivka.

Two Ukrainian soldiers were wounded in action over the period under review.

Ukraine's Joint Forces fired back in response to every attack, using weapons that are not banned under the Minsk agreements.

According to Ukrainian intelligence reports, one enemy troop was wounded on July 13.

Since Sunday midnight, Russia-led forces have already mounted four attacks on JFO positions in eastern Ukraine.