Authorities said the al Qaeda-linked militants fired two mortar rounds into the frontier town of Liboi during a half-hour assault at night. No casualties were reported.
“The rebels surrounded the station, they made an advance towards the armoury but the officers on duty managed to repulse them,” a senior police officer told Reuters on condition of anonymity.
Security forces chased the rebels who crossed back into Somalia. Residents said people had started to flee Liboi and other areas around the border over fears the attacks would escalate.
“We are worried. They have attacked police officers twice since Monday,” said 40-year-old resident Abdirizak Ali.
Wednesday’s incident is the latest in a series of cross-border attacks by al Shabaab militants. On Monday, a police officer was shot in a remote border outpost in an ambush blamed on the insurgents.
The insurgents have threatened to strike Kenya, east Africa’s biggest economy, with an assault similar to the twin suicide-bomb attack on the Ugandan capital, Kampala, last year.
In Mogadishu, the U.N. special representative to Somalia said he would invite the country’s president, prime minister and speaker of parliament to meet donors and discuss what next after the interim administration’s mandate ends in August.
There is broad agreement outside Somalia that the interim government has failed to make political progress and achieve security gains against the insurgents. But both parliament and the government have unilaterally extended their terms in office.
Ambassador Augustine Mahiga said the meeting would take place in the Kenyan capital, Nairobi, in April.
In a separate incident on Wednesday, a police officer was wounded in a bomb blast near a police station in southern Somalia, close to the border with both Kenya and Ethiopia.
“The bomb was remote-controlled. They targeted the police station in Luq,” said Nur Mattan, a security official from the district.
One Somali government soldier was wounded in the attack.
Al Shabaab controls large swathes of central and southern Somalia, which has not had an effective central government since the 1991 overthrow of dictator Mohamed Siad Barre. (Additonal reporting by Ibrahim Mohamed in Mogadishu; writing by Aaron Maasho; editing by Richard Lough)