MOSCOW, June 6. /TASS/. At night, terrorist groups increased intensity of fire from the area of the Castello trade center, which had earlier been under control of "moderate opposition", a spokesman for the Russian center for reconciliation of the warring sides in Syria said.

Mortar shelling of the Kurdish quarter of Sheikh Maqsood in the northern part of Aleppo by militants of Jabhat al-Nusra, banned in Russia, continue," he said.

"Fierce fighting is underway on the outskirts of the Sheikh Maqsood quarter. Militants keep concentrating armored vehicles and vehicles with heavy machineguns, broadly used for fire support, to that area," the spokesman said.

Over 2,000 militants from various terrorist groups and detachments of the so-called "moderate opposition" are concentrated in the area of Sheikh Maqsood.

The day before, the neighborhood was subjected to considerable destruction. As a result of shelling by terrorist groups’ militants, a police station and a number of residential and administrative buildings nearby were destroyed. Tens of civilians were killed or injured, the bulletin said.

Earlier, the reconciliation center said militants of Jabhat al-Nusra shelled from mortars and multiple launch rocket systems an area north of Aleppo.

"As a result of shelling of civilian quarters, a trade center, residential and administrative buildings, private constructions were destroyed, there are casualties and those injured among civilians," the center said.

The ceasefire regime took effect in Syria on February 27. Shortly before, the UN Security Council adopted a resolution supporting a cessation of hostilities. The document drafted by Russia and the United States was backed by all 15 Security Council member states.

The ceasefire regime does not cover the Islamic State and Jabhat al-Nusra terrorist organizations as well as other groups ruled terrorist by the Security Council.

Russia takes an active part in the Syrian settlement effort. It helps Syria's authorities fight terrorists and has conducted mine clearing work in the ancient city of Palmyra.

Russia’s Aerospace Forces started delivering pinpoint strikes in Syria at facilities of Islamic State and Jabhat al-Nusra, which are banned in Russia, on September 30, 2015, on a request from Syrian President Bashar Assad.

On March 14, 2016, Russian President Vladimir Putin ordered to start, from March 15, withdrawing the main part of the Russian Aerospace Forces’ group from Syria. Putin said the tasks set before the military "have been fulfilled on the whole." Russian Deputy Defense Minister Nikolai Pankov said strikes on terrorists will continue to be delivered.

During Russia’s operation against the Islamic State and Jabhat al-Nusra that lasted nearly six months, Syrian forces recaptured nearly 400 inhabited localities with support from Russia’s aircraft. Serious problems were created for illegal oil trade, which is the key source of income for terrorists; the main routes of supply of arms and ammunition to militants were blocked.