Boni Forest lies on the Kenya-Somalia border in the coastal county of Lamu and is a notorious al-Shabaab hideout. Photo: Getty Images

An unspecified number of soldiers have died following a helicopter crash during a patrol mission in Lamu County along the northern coast on Monday night.

The accident occurred while the soldiers were patrolling Boni Forest in Lamu, the Kenya Defence Forces (KDF) said in a statement. The forest is notorious for being a hideout for the Somali-based al-Shabaab terror group.

"The crew and other military personnel onboard were part of an air surveillance squadron intensifying day and night patrols and surveillance for the ongoing Operation Amani Boni," the KDF said.

"The leadership and entire KDF fraternity condole with the families of the crew," the statement added.

The Kenyan military has launched an inquiry to determine the cause of the incident with investigators sent to the crash site.

Kenyan security forces have been combing the Boni forest in a bid to flush out al-Shabaab militants. The forest sits along the Kenya-Somalia border and stretches to the Indian Ocean Coast.

The military stated that more information will be released once all of the deceased's families have been notified.

TRT Afrika