Kenya's police chief today asked residents to be "extra vigilant" of attacks in the week following Sunday's anniversary of the Westgate Mall attack.
David Kimaiyo said police have doubled patrols across the country and asked entertainment facilities to continuously review and update security arrangements.
Al-Shabab militants from Somalia claimed responsibility for the Sep 21 Westgate Mall attack that left 67 people dead.
Gun and grenade attacks have increased in Kenya, starting in October 2011 when Kenya sent its troops to Somalia to fight the militants.
Al-Shabab vowed retribution for Kenyan troop presence in Somalia. More recently, the militants also vowed to avenge the death of leader Ahmed Abdi Godane, who was killed by an American airstrike earlier this month.
On Thursday, one person died and 13 others were wounded in gun and grenade attacks in the towns of Wajir and Garissa.
Kimaiyo extended by a month the dusk-to-dawn curfew placed on Lamu County at the Kenyan coast, where at least 65 people died in June in an al-Shabab attack.
The Kenya police force and army have been widely criticized for the response on Westgate attack. It took at least two hours before the Kenya police tactical team went into the mall which had been attacked by four gunmen.
Lack of coordination between the military and the police tactical teams led to friendly fire in which one police officer was killed and others wounded.
The police chief today rejected criticism that the security agencies were disorganized and uncoordinated leading to a slow response to the Westgate Mall attack.
"It was done professionally," he said. "It's not a matter of saying it was not well done it was not coordinated. If you were in my shoes at that particular time what could you have done better than what we did?"
The attackers were eventually killed by a fire caused by a high explosive rounds shot at the mall by the Kenyan military.
Kenya is struggling to reform The National Police Service, whose reputation has been marred by constant accusations of widespread bribe-taking, unresponsiveness and human rights abuses, including extra-judicial executions.
