Image copyright AFP Image caption North Korea periodically detains foreigners, particularly those linked to religious activity

A pastor from a Canadian church has failed to return from a humanitarian visit to North Korea, an official from his church says.

Reverend Hyeon Soo Lim, 60, travelled to North Korea on 31 January and was due to leave on 4 February.

He had been to North Korea many times, his church said, but this was the longest he had been out of touch.

Canadian officials said they were in contact with Rev Hyeon's family and had offered consular assistance.

North Korea periodically detains visiting foreign nationals, particularly those linked to religious activity - which is restricted inside the country.

US citizens are generally held the longest. North Korea is seen as using them to try to extract political concessions.

But citizens from nations of less political importance to Pyongyang can be freed quickly. An Australian missionary detained in February 2014 for leaving Christian material at a tourist site was swiftly deported.

Church officials initially wondered whether Rev Hyeon had become caught up in a 21-day quarantine North Korea said it was imposing on travellers potentially exposed to Ebola.

"We didn't want to cause unnecessary hysteria, just make sure he is OK," Reuters news agency quoted Lisa Pak, a spokeswoman for the Light Korean Presbyterian Church in Toronto, as saying.

"He's very non-political; he just wants to help the people."

She said Rev Hyeon helped oversee facilities for the elderly and orphans in North Korea.

Canada advises against all travel to North Korea and has no diplomatic presence in the country.