More than 100 Ukrainian schoolchildren will have unusual tales to tell their mates when classes resume, after spending part of their summer vacations undergoing training by the National Guard.

The training at a National Guard camp about 75 kilometers (45 miles) from Kiev taught children aged 11-15 rudimentary military skills and gave them a taste of army life in courses over three days. At night the children were quartered in army tents; by day they got instruction in marksmanship, hand-to-hand fighting, weapons maintenance, first aid, map reading and orienteering.

For 11-year-old Oleksander Olinichenko, whose mother and father are both in the Ukrainian army, the camp was a chance to pursue his interest in all things military, as well as show his patriotism.

"''I like everything here, they teach me to take apart and to assemble the assault rifle, they teach us hand-to-hand fighting, first aid - it's very interesting," said Oleksander, his face disguised by military goggles and a regulation helmet.

Some children are from military families in Kiev, others are refugees who relocated to the Ukrainian capital, having left their homes in eastern Ukraine when fighting broke out in 2014. Some of the children chosen to attend the camp come from low-income families, according to the National Guard press office.

National Guardsman Oleksander Honcharenko gave the children instruction in hand-to-hand fighting and karate. He told The Associated Press he and all the other instructors at the camp had served in the Ukrainian army during the conflict in East Ukraine.

"I think every person has to be able to defend himself and his relatives, his nearest and dearest, his family and property. The most important thing is to be able to react quickly in an extreme situation and to make the right decision. The kind of the hand-to-hand fighting that we teach helps them develop such abilities," said Honcharenko, who is vice president of the Ukrainian Karate Association.

Ukraine's President Petro Poroshenko recently vowed to increase troop numbers to fend off attacks by Russia-backed separatist rebels and warned his countrymen that there is still the threat of a "large-scale invasion." He claimed that Russia had massed about 50,000 troops on the border with Ukraine, still had 9,000 soldiers in eastern Ukraine and had supplied the rebels with about 500 tanks and 400 pieces of artillery.