Bomb threats forced eight universities in Japan to temporarily close on Monday.
The education ministry says at least 19 public and private universities in 11 prefectures, including Hiroshima and Okayama, received faxed bomb threats on Monday morning.
The messages said that bombs were planted at the universities and demanded the transfer of 300,000 yen, or about 2,300 dollars, into a designated account. The messages reportedly included the name of a specific lawyer as the sender.
Of the 19 universities, eight cancelled morning or afternoon classes.
No damage has been reported so far.
The universities concerned are working with police and remain vigilant.
An official at Tsuru University in Yamanashi Prefecture says the university temporarily closed because the officials put top priority on the safety of students and school personnel. The official also says they will consider offering makeup lectures or other measures, as many students missed classes ahead of regular tests.