The head of a school in Japan says a group of exchange students and their teachers were trapped in a collapsed building after the New Zealand earthquake.

Head of the Toyama College of Foreign Languages Hisao Yoshida says a group of 21 students and two teachers were eating lunch in a cafeteria when the quake struck Tuesday.

He said one of the teachers called her family in Japan from inside the building, and that one in the group had suffered a broken leg.

An official from Toyama Prefecture, on the western coast of Japan, said nine students and two of the teachers were accounted for, but another 12 students could still be trapped.