Extremists from neighboring Somalia beheaded nine civilians in an early morning attack on a southeastern village in Kenya, government officials said on Saturday, as concerns grew that the group known as the Shabab has taken up a bloody new strategy.

The attack occurred in Jima, a village in Lamu County, said James Ole Serian, who leads a task force of security agencies combating the terror group.

Beheadings by the Shabab have been rare in Kenya, though the group has carried out dozens of other deadly attacks there over the years. In recent weeks, the country has seen an increase in attacks claimed by the group, raising security concerns about next month’s presidential election.

The Shabab, which has links to Al Qaeda, has vowed retribution against on Kenya for sending troops into Somalia to fight it in 2011.