PORT-AU-PRINCE (Reuters) - Heavy rains are expected to continue across Haiti on Friday, the national weather service said, after killing at least 13 people in the north and damaging thousands of homes.

"If you live by a river, ravine or mountainside, move," Haiti's civil protection body warned.

Nearly all of the country is at risk of "frequent and intensifying" to "significant" thunderstorms through Friday evening, the weather service added, warning of flash floods.

Outside of the northern town of Cap-Haitien, rains caused a landslide which caused several houses to collapse and killed 12, Haiti's disaster agency said in a statement released on Thursday afternoon.

More than 2,000 houses were flooded with water runoffs overflowing and sewers clogged.

The north is Haiti's agricultural breadbasket, although gangs have strengthened their hold over the region in recent years and damaged or stolen crops and demanded bribes from farmers.

The disaster agency found "significant losses" in livestock in early reports from the north, while the country's center region also saw farms "devastated."

Through the weekend, moderate-to-heavy rains were expected to continue, particularly in the north and south, the weather service said.

The destruction comes during a time of political turmoil for Haiti, with a newly installed transition council suffering from infighting and gangs ramping up violence across the Caribbean nation in recent months.

(Reporting by Harold Isaac in Port-au-Prince and Kylie Madry in Mexico City; Editing by Sandra Maler)