KYIV. July 22 (Interfax) - Accumulation of hostile troops and heavy armaments in key sectors of the frontline has been the trend of the last few days in the army operation zone in Donbas, Ukrainian Presidential Administration spokesman Andriy Lysenko has said.

"First and foremost, this is the question of Vuhlehirsk, northern parts of Horlivka and western areas of Donetsk. This is why the enemy is constantly staging armed provocations on these lines of defense. The situation is rather quiet in other sectors of the contact line," he said at a press briefing in Kyiv on Wednesday.

Sporadic armed provocations have been observed near Stanitsa Luhanska, Stary Aidar, Zolote and Troitske in the Luhansk area, Lysenko said.

"Only small arms and machineguns have been used; the use of heavy armaments has not been observed," he said.

Tensions are flaring in the Svitlodarsk-Horlivka agglomeration in the Donetsk area. Ukrainian positions have come under the attack of 120mm mortars and 152mm guns. Hostiles shelled Ukrainian positions on a long stretch of the frontline from Sanzharivka to Novhorodske, the spokesman for the Ukrainian Presidential Administration said.

"As a result of the use of such powerful weapons, both our frontline positions, populated areas close to the frontline and strategic infrastructures, for instance the dam in the town of Myronivske, have come under fire of the hostiles," Lysenko said.

He added that two women were injured in shelling near Mayorsk.

The fighting continues round-the-lock in the western suburbs of Donetsk, from Avdiivka to Maryinka, Lysenko said.

He said there had been sporadic mortar and tank attacks on the Ukrainian positions.

"Yet the use of artillery [by the militia] has not been observed in that area. The truce stands south of Donetsk," the spokesman continued.

A brief tank attack on Ukrainian army positions happened in an area between Komsomolske and Volnovakha in the Mariupol sector.

The sound of gunfire was audible in Shyrokyne. "Those provocations were sporadic and aimed to put negative psychological pressure on the servicemen