Nairobi - Kenya was on a heightened terror alert Friday after recent suicide bombings in neighbouring Somalia and the arrest Thursday in Nairobi of a man carrying what were believed to be detonators.

Five suicide bombs in the breakaway Somali regions of Somaliland and Puntland killed at least 26 people Wednesday.

Kenyan government spokesman Alfred Mutua said the fact that the bombings took place as Somali leaders were meeting with regional heads of state in Kenya at the same time had raised fears in Kenya.

Somali insurgent group al-Shabaab, which is battling the transitional federal government in Central and Southern Somalia, had earlier warned that it would attack Kenya if it went on with plans to train Somali security forces.

Al-Shabaab is believed to have strong links to al-Qaeda.

An internal memo sent by the Kenya Revenue Authority warned that al-Qaeda was planning to attack "Western interests" in Kenya and Uganda in the coming days and asked its staff to increase their vigilance levels.

The KRA said that al-Qaeda operative Harun Fazul, also known as Fazul Abdullah Mohammed, was behind the plans.

Fazul is believed to have been the mastermind behind the 1998 bomb attacks on US embassies in Nairobi and Dar es Salaam, Tanzania, which killed over 200 people and injured 4,000.

Authorities believe Fazul is now based in Somalia, although Kenyan police narrowly missed capturing him during a recent visit to Kenya.

Kenyan police on Thursday also seized around 600 bomb detonators bound for northeast Kenya, near the Somali border, from a man on a bus in Nairobi.

Almost daily battles have blighted Somalia since Ethiopian troops invaded in 2006 to kick out the Islamist regime and put the transitional federal government back in power.

Islamist insurgents have since fought back, taking over the key port town of Kismayo and hammering Ethiopian, government and AU peacekeeping troops.

Civilians have borne the brunt of the fighting, with aid agencies now estimating almost 10,000 have died since the insurgency began in early 2007. (dpa)