"No one has been allowed. We are waiting for official information of the border guards with explanations," said Wegrzyn who is meeting the Russian colleagues at the Terespol border crossing in eastern Poland, TASS wrote.

"They have been held for several hours and something was being checked," he added.

Read alsoPutin's Angels: the bikers battling for Russia in Ukraine - The GuardianA spokesman for the Polish border guards in Terespol told reporters on Sunday the entry ban comes due to threat to the republic's security.

"We have banned entry to seven bikers. Four of them had passports of Slovakia, two others of Germany and one of Russia," Dariush Senitsky said. "The reason for the ban is the threat to public order and security of the state," he said, adding: "We acted in line with the law."

Read alsoPolish Defense Minister announces full-fledged NATO membershipSeveral dozen bikers from Slovakia, the Czech Republic, Germany and also Poland's Katyn Rally motorcycle club were due to meet with the bikers on the Polish side of the border. They are continuing the motor rally. The column consisting of around 100 people is heading to Warsaw to lay flowers at the Tomb of the Unknown Soldier and the Soviet military cemetery.