SOFIA, March 2 (Xinhua) -- Bulgarian border police detained 41 illegal immigrants on Friday at the Kulata checkpoint who had been hidden in a Romania-registered truck coming from Greece, officials said.

The migrants, including 29 men, five women and seven children, were discovered after an X-ray examination, Bulgaria's Interior Ministry said in a statement.

It is not clear up to now what the migrants' nationalities are, the statement said.

The driver, a 50-year-old Romanian citizen, was also arrested.

In 2017, the Interior Ministry arrested 743 illegal immigrants trying to enter Bulgaria.