Clashes erupted on Thursday in the government-held Somali border town of Balad Hawa as residents headed to evening prayers. Mortar fire reverberated through the dusty streets until after midnight when Al-Shabab fighters retreated.

A Kenyan security officer at the border said scores of Kenyan troops were deployed along the frontier as a precaution.

Resident Ahmed Osman said he counted 32 corpses in Balad Hawa on Friday morning. Somali forces put the known toll at 27 and said a unidentified number of their own troops were killed.

Others said the fighting had triggered an exodus from the town, with hundreds fleeing toward Kenya and nearby Ethiopia.

“Al-Shabab attacked our defensive positions...but we later defeated them and kicked them out of the town and surrounding areas,” said Sharif Abdiwahid, a spokesman for the joint force of government troops and Ahlu Sunna Waljamaca militia.

Kenya, east Africa’s largest economy, has long cast a wary eye at its lawless neighbor where first warlords and now Islamist insurgents have reduced government to haplessness.

Those living in Kenya’s remote northeastern provinces have reported increasing cross-border raids by Al-Shabab.

Twice hit by Al-Qaeda-linked attacks, Kenya has trained thousands of Somali recruits to beef up troops loyal to Somali President Sheikh Sharif Ahmed, a move that has drawn condemnation from Al-Shabab.

“The town is empty now. We can say 90 percent of the people have fled either to Mandera in Kenya or Dollow in Ethiopia,” said Barre Adan Shire, a Somali lawmaker and commander of a local pro-government militia.