Official: 2 tank columns from Russia enter Ukraine

NOVOAZOVSK, Ukraine -- Ukrainian security council spokesman Col. Andriy Lysenko says Ukrainian forces were fired at using Grad missile systems from Russian territory at about 11 a.m.

Lysenko says about an hour and a half later, two columns, including tanks and other fighting vehicles began an attack.

They later entered Ukraine from Veselo-Voznesenka and Maximovo of the Rostov region in Russia.

Ukrainian border guards retreated because they didn't have heavy equipment.