NNA -  Moscow on Tuesday voiced deep concern on the second day of the most serious armed incursion to date over its border with Ukraine, after explosive strikes forced civilians to flee.

Russia said the Belgorod border region had come under sustained artillery and mortar fire during fighting with a group that it claimed had crossed from Ukraine.

Belgorod's governor said civilians have been evacuated from nine border villages in the region, which has previously faced shelling attacks that have killed dozens of people since Moscow launched its offensive last year.

"What happened yesterday is a cause for deep concern and once again confirms that Ukrainian militants continue their activities against our country," Kremlin spokesman Dmitry Peskov told reporters on Tuesday. -- AFP

=================