Kenya's president has fired his security minister and police chief after the latest al-Shabab attack within Kenyan borders. He also promised to increase his efforts in battling al-Shabab in the face of increasing attacks from the Islamic extremist group.

Kenya's Uhuru Kenyatta condemned al-Shabab's Monday attack that killed 36 Kenyan quarry workers near the border with Somalia, reports The Guardian. In a speech before the nation, Kenyatta reassured Kenyans that he would continue fighting al-Shabab.

"We will not flinch or relent in the war against terrorism in our country and our region," he said. "We shall continue to inflict painful casualties on these terrorists until we secure our country and region. Our stability and prosperity depends on a secure neighborhood."

Kenyatta also accepted the resignations of his security minister, Joseph ole Lenku, as well as the police chief.

According to CNN, the attack took place near the border town of Mandera, at a quarry in Kormey. Al-Shabab sources said the group separated the Muslims from the non-Muslim workers and executed the latter, killing at least 36.

Al-Shabab has been attacking Kenya since the nation sent troops into conflict-ridden Somalia to protect its border from the insurgents. The terrorist group has continued retaliating by executing Kenyan civilians.

"Our Mujhahideen forces are always ready to launch frequent deadly cross-border attacks against Kenya as a revenge," group spokesman Sheikh Ali Dheere said in a statement.

In his speech, Kenyatta urged Kenyans to choose a side, reports the BBC.

"This is a war against Kenya and Kenyans," he said on national television. "It is a war that every one of us must fight."

"The time has come for each and every one of us to decide and choose - are you on the side of an open, free, democratic Kenya... or do you stand with repressive, intolerant extremists?"

In its latest attack, al-Shabab attacked a U.N. convoy with a car bomb killing four Somalis, reports Reuters.