Kiev ( Ukraine ) - (AFP) - Ukraine announced Wednesday that it had recovered several towns from the Russians in the south of the country, and welcomed the delivery of a new air defense system, expecting a "new era" after two days of intense bombing.

The country was targeted a few days ago with a barrage of missiles and drones that specifically targeted the civilian energy infrastructure, in strikes that Russian President Vladimir Putin considered to be a retaliation for the bombing attack that destroyed the Crimean bridge, which Moscow described as a "terrorist" and attributed to Kiev.

And on Wednesday, the Russian security services announced that they had arrested eight people, including five Russians, on suspicion of their involvement in the bombing that targeted the Crimean Bridge on Saturday.

It also announced the thwarting of two attacks, which it said the Ukrainian intelligence was planning to carry out on Russian soil.

NATO Secretary-General Jens Stoltenberg announced that Ukraine's Western allies are considering providing Kiev with more air defense systems to protect it from "indiscriminate" Russian missile attacks across the country.

"We will discuss how to enhance support for Ukraine, and the priority will be for more air defense systems for Ukraine," Stoltenberg said at the start of a NATO meeting on arms deliveries to Kiev.

Putin promised a "harsh" response to any further attacks on Russia and what it considers its territory and infrastructure, in light of Moscow's annexation of Crimea in 2014 and then four other Ukrainian regions in September.

Despite the Kremlin's threats, Kiev pledged to restore the peninsula and the four regions annexed by Russia in eastern and southern Ukraine.

And on Wednesday, Kiev announced that it had recovered five towns in the Kherson region, which is one of the four regions that Moscow announced its annexation, in the latest setback for the Russian army, which has been retreating in this region, in the northeast and in the east since the beginning of September.

However, the Ukrainian presidency referred to the response of the Russian forces to the operation, explaining, "The sites of our units continue to be bombed to deter the counter-attack along the line of contact."

Meanwhile, the Russian army announced that it had repulsed Ukrainian attacks in the Donetsk, Lugansk, and Kharkiv regions in eastern Ukraine.

At least eight people were killed in Russian bombing of a market in the city of Avdiivka in eastern Ukraine, near the front lines, according to the region's governor, Pavlo Kirilenko.

"There is no military logic in this type of bombing, other than the wild desire to kill as many of our people as possible and terrorize the rest," he said in a post on social media.

In late August, the Ukrainian army announced the launch of its counteroffensive.

After regaining almost complete control of the Kharkiv region in the north-east of the country, Ukrainian forces recently announced more field gains in the east and south of the country.

On Wednesday, the Kremlin announced that it expects Turkish President Recep Tayyip Erdogan to present to his Russian counterpart a concrete proposal related to mediation over the conflict in Ukraine, noting that the two presidents will meet Thursday in Kazakhstan.

The Kremlin's diplomatic advisor, Yuri Ushakov, told reporters, "The Turks are offering their mediation. If (Russian-Ukrainian) contacts will take place, they will take place on" Turkish territory. "Erdogan may formally propose something," he added, expecting a "useful and interesting discussion."

Ukraine has inflicted several defeats on Russian forces since September, which prompted the Russian president to issue orders to mobilize hundreds of thousands of reservists to try to reverse this trend.

The explosion that destroyed part of the Crimean bridge was seen as a humiliation for Putin, who wanted to present it as a symbol of Russian power. This bridge is also essential for supplying Russian forces in southern Ukraine.

And US President Joe Biden announced on Tuesday that his Russian counterpart "clearly" miscalculated the situation in Ukraine, adding that he "completely miscalculated" the resistance he would face.

The US President said that Putin "thought that he would be greeted with arms (...) and I think that his calculation was completely wrong."

"A new era of air defense has begun" in Ukraine, Ukrainian Defense Minister Oleksiy Reznikov said in a tweet, adding that "the German Iris-T is already here. The American NASAMS will come after it."

Reznikov said he met his US counterpart Lloyd Austin and General Mark Milley to discuss "strengthening the combat capabilities of the Ukrainian army".

And on Tuesday, Ukrainian President Volodymyr Zelensky called, during a virtual meeting of the Group of Seven, to help create an "air shield" over Ukraine, warning that Putin "still has the means to escalate."

The 27 members of the European Union agreed to form a military mission to train Ukrainian forces in a number of bloc countries.

It is assumed that 15,000 soldiers will participate in the first training round, according to diplomats.

In addition to the infrastructure, the Russian strikes hit a park, a playground, a bridge and a pedestrian walkway in central Kiev on Monday. The capital has not been targeted since the end of June.

In the east, the Ukrainian authorities announced the discovery of two new mass graves in towns in the Donetsk region that were finally recovered from Russian forces.

In Liman, a railway junction that was recaptured in early October, a forensic team exhumed dozens of bodies, an AFP journalist reported.

"We have already found more than 50 bodies of soldiers and civilians. We have a long trench, a mass grave, where we found bodies and body parts," said the governor of Donetsk region.

Russia has been accused of numerous abuses - torture, rape and summary executions - in the cities from which it withdrew. However, Moscow has consistently denied the involvement of its soldiers despite mounting evidence.

On Wednesday, Putin stressed that his country is a reliable source of energy. After explosions damaged Nord Stream gas lines linking Russia with Europe, Putin said "the ball is now in the European Union's court" to resume supplies, adding: "If they want to, the taps can be opened and that's all."