Moldova said Monday that Russian cruise missiles targeting Ukraine had crossed its airspace, and summoned Moscow's envoy to demand an explanation.
"Three cruise missiles launched on Ukraine this morning from Russian ships in the Black Sea crossed Moldova's airspace," foreign minister Nicu Popescu said on Twitter.
"I instructed that Russia's ambassador be summoned to provide an explanation."
Popescu expressed outrage at the many strikes carried out on Ukrainian cities on Monday, a day after Moscow blamed Ukraine for an explosion on a bridge connecting Crimea to Russia.
"Appalled by multiple Russian rocket strikes on cities across Ukraine, including the capital Kyiv, striking civilian targets. Russia must stop killing," he said.
He said his office had been in touch with Moldovan embassy staff in Kyiv and that they were safe "and sheltering from these senseless attacks on civilians".
"Our thoughts are with the victims of the brutal strikes," Popescu said.
Like Ukraine, tiny Moldova is a former part of the Soviet Union with a pro-Western government.
Hundreds of thousands of Ukrainian refugees have flooded into the country since Russia sent troops into Ukraine.
Moldova was along with Ukraine granted candidate status by the European Union in a show of support in the face of Russia's offensive.
Moldova has a small breakaway region, Transnistria, which is armed and supported by Russia.