GENEVA (Reuters) - Around 30,000 people fled into Cameroon at the weekend from the Nigerian city of Rann, fearing an attack by Boko Haram militants, the U.N. refugee agency said on Tuesday.

UNHCR spokesman Babar Baloch told a regular U.N. briefing in Geneva that the exodus followed the departure of Cameroonian forces who had moved to secure the city, following an attack by Boko Haram on Rann on Jan. 14.

“Because Cameroon is part of the Multi-National Joint Task Force, their military went in to secure Rann. So it was ... peaceful (for a while) but as far as we understand now, that Multi-National Task Force has left,” Baloch said.

Two security sources said Nigerian soldiers had been overrun by the initial attack on Jan. 14, and the Nigerian military had abandoned Rann again after the multi-national force left because they did not have enough men, equipment or weapons to defend it.

Refugees reported that Boko Haram had promised to return to the city, which originally had an estimated population of about 80,000, Baloch said.

“So all the population seems to be panicking and they are on the run as a pre-emptive measure to save their lives,” Baloch said. “This is quite worrying and alarming.”

Boko Haram returned on Monday and entered Rann unopposed, burned down part of a camp and left again, the security sources said.

“The Nigerian soldiers fled camp and everyone is escaping to Cameroon,” said Midjiyawa Bakary, governor of the Extreme North region.

“We do not repel them, that would be suicidal. They are welcome. All the refugees are taken in charge by humanitarian (authorities)… We are communicating with UNHCR in Cameroon and Nigeria, working hand in hand to take these refugees in charge, guarantee their security and alleviate their suffering.”

Immediately after the Jan. 14 attack, 9,000 people fled into Cameroon but they were refused asylum and sent back to Nigeria by Cameroonian authorities, UNHCR has said previously.

It was not clear how many people were left in Rann, Baloch said.