Eleven students from a Japanese school were missing Tuesday night and another was trapped in a building collapsed by a strong earthquake in Christchurch, New Zealand, Japanese authorities and school officials said.

The 12 students were in a group of two teachers and 21 students from Toyama College of Foreign Languages, they said.

The school was having difficulty gathering information about the students and teachers due to power blackouts and disrupted communications, the officials said.

Of the 11 people whose whereabouts were confirmed, two students were hospitalized, one having sustained a broken bone.

The teacher who was leading the group e-mailed her family around 10:20 a.m. Tuesday, Japan time, to say she was trapped under rubble and had seven students near her at the time.

She was later rescued along with five of the students. The other teacher, a male New Zealand national, was also safe, the officials said.

There were 20 first-year students, aged from 18, and one second-year student in the group, they said.

The teachers and students left Toyama Prefecture on Thursday and were scheduled to return March 13. They were taking part in an academic program at the King's Education College.