KYIV, UKRAINE -- Ukrainian authorities arrested Wednesday a man they accused of helping Russia direct a missile strike that killed at least 10 people, including three children, at a popular pizza restaurant in a city in east Ukraine.

The Tuesday evening attack on Kramatorsk wounded another 61 people, Ukraine's National Police said, in the latest bombardment of a Ukrainian city -- a tactic Russia has used heavily in the 16-month-old war.

Two sisters, both age 14, died as result of the attack, the educational department of the Kramatorsk city council said. "Russian missiles stopped the beating of the hearts of two angels," it said in a Telegram post.

The other dead child was 17, according to Prosecutor General Andrii Kostin.

The attack also damaged 18 multi-storey buildings, 65 houses, five schools, two kindergartens, a shopping center, an administrative building and a recreational building, the regional governor, Pavlo Kyrylenko, said.

Rescuers are still searching the rubble for bodies and more survivors.

The strike, and others elsewhere across Ukraine, indicated that the Kremlin is not easing its aerial onslaught despite turmoil caused by a short-lived armed uprising last weekend. There has also been no apparent military push by Ukraine to exploit that turmoil, though Kyiv has been tight-lipped about recent battlefield developments.

Officials initially blamed the strike in Kramatorsk on an S-300 missile, a surface-to-air weapon that Russia's forces have repurposed for loosely targeted strikes on cities, but the National Police later said Iskander short-range ballistic missiles were used.

Kramatorsk is a front-line city that houses the Ukrainian army's regional headquarters. The pizza restaurant was frequented by journalists, aid workers and soldiers, as well as locals.

The Security Service of Ukraine said it had detained a man whom it suspects directed the strike on the restaurant, who is an employee of the local gas transportation company.

He filmed the restaurant for the Russians and informed them about its popularity, the Security Service said in a Telegram post.

It provided no evidence for its claim. Russia has insisted during the war that it doesn't aim at civilian targets, although its air strikes have killed many civilians.

Kramatorsk is located in Donetsk, one of four Ukrainian provinces that Russia claimed to annex last September but does not fully control. Russia has also occupied Crimea since 2015.

Ukrainian-held parts of the partially occupied provinces have been hit especially hard by Russian bombardment and are a key barrier to resolving the war.

The Kremlin demands that Kyiv recognize the annexations, while Kyiv has ruled out any talks with Russia until its troops pull back from all occupied territories. Kyiv recently launched a much-anticipated counteroffensive to take back occupied territory.

Russia, meanwhile, has stepped up its air campaign in Ukraine while fighting continues along the front line.

Russian forces on Monday and overnight also shelled 16 settlements in the southern Zaporizhzhia region, the Ukrainian presidential office reported.

It said that a 77-year-old civilian was killed in the front-line town of Orikhiv, and that Russian shelling wounded three people in a nearby village recently retaken by Kyiv.

Also, a Russian supersonic cruise missile slammed into a cluster of holiday homes in central Ukraine, sparking a fire which injured a child, the presidential office said.

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Associated Press Writer Yuras Karmanau in Tallinn, Estonia, contributed to this report.