REFILE-WRAPUP 11-Russian missile strikes near Ukraine's Odesa kill 21

(Refiles to correct attribution in par 11)

* Missiles hit apartments, resort on southern coast

* Ukraine's Zelenskiy says sites deliberately targeted by Russia

* Moscow denies targeting civilians

By Iryna Nazarchuk

SERHIIVKA, Ukraine, July 1 (Reuters) - Russia flattened part of an apartment building while residents slept on Friday in missile attacks near Ukraine's port of Odesa that authorities said killed at least 21 people, hours after Russian troops abandoned the Black Sea outpost of Snake Island.

Residents in the resort village of Serhiivka helped workers pick through the rubble of the nine-storey apartment block, a section of which had been destroyed in the early-morning strike.

Walls and windows of a neighbouring 14-storey apartment block were damaged by the blast wave. Nearby holiday camps were also hit.

"We came here to the site, assessed the situation together with emergency workers and locals, and together helped those who survived. And those who unfortunately died. We helped to carry them away," said Oleksandr Abramov, who lives nearby and had rushed to the scene when he heard the blast.

Serhiy Bratchuk, spokesman for the Odesa regional administration, said 21 people had been confirmed killed, including a 12-year-old boy. Among the fatalities was an employee of the Children's Rehabilitation Center set up by Ukraine's neighbour Moldova in the resort.

The regional governor said the missiles had been fired from the direction of the Black Sea.

The Kremlin denied targeting civilians.

"I would like to remind you of the president's words that the Russian Armed Forces do not work with civilian targets," Kremlin spokesperson Dmitry Peskov said.

LONG-RANGE ATTACKS INTENSIFY

In his nightly video address on Friday, Ukrainian President Volodymyr Zelenskiy denounced the strike on the apartments and seaside site as "conscious, deliberately targeted Russian terror and not some sort of error or a coincidental missile strike."

The strike on Serhiivka took place shortly after Russia pulled its troops off Snake Island, a strategically important outcrop about 140 km (85 miles) southeast of Odesa that it seized on the war's first day.

Chief of Ukraine's General Staff Valeriy Zaluzhny accused Russia of failing to abide by its assertions that it had left Snake Island as a "gesture of good will". On his Telegram channel, Zaluzhny said two Russian warplanes had taken off from a base in Crimea and bombed targets on the island on Friday evening.

He posted a video of what he said was the attack. Reuters had no way of confirming the video or the Russian action. There was no immediate Russian comment.