Kenyan officials say a security officer was wounded Tuesday when Somali Islamist militants ambushed a patrol on the Kenyan-Somali border.

The officials say the incident happened in the Kenyan border district of Lagdera.

They say al-Shabab fighters opened fire on a Kenyan border patrol, hitting the officer. A Kenyan journalist told VOA's Somali service that the man was taken to a local hospital.

Kenyan security forces have sent reinforcements to the area.

Kenyan authorities have been on heightened alert since the July 11 suicide bombings in Uganda's capital that killed 76 people. Al-Shabab claimed responsibility for the attacks.

Al-Shabab has crossed into Kenya several times before to attack towns and villagers. The group accuses Kenya of supporting anti-Shabab militias in Somalia.

The insurgent group is trying to topple the Somali government and set up a strict Islamic state.

Last week, police in Kenya arrested several men accused of having ties to al-Shabab.

Some information for this report was provided by Reuters.