Between 10 and 20 New Zealanders are unaccounted for in the provinces of Japan affected by the massive earthquake and tsunami, New Zealand officials say.
New Zealand's ambassador in Japan, Ian Kennedy, says the phone system is now up and running and embassy staff are working hard to reach those who have not been in contact.
Mr Kennedy says officals have also been contacting people using Skype and Facebook and will keep using all means to get hold of people.
He says that, in total, about 3500 New Zealanders are listed as being in Japan for three months or more and another 3000 more are estimated to be in the country on shorter visits.
On Sunday 828 New Zealanders had registered as being in Japan.
The Ministry of Foreign Affairs and Trade (MFAT) advises New Zealanders with concerns about family in Japan to try to contact them directly in the first instance. If they cannot make contact and family members are known to be in the north east of Japan please contact MFAT on 0800 432 111. If calling from overseas call +64 4 439 8000.
MFAT is advising against all non-essential travel to Tokyo, and affected areas in the northeast, because services like transport and electricity have been disrupted.