Head of Nairobi police operations Julius Ndegwa said Wednesday the 11 suspected gangsters were gunned down in three separate incidents in Nairobi's residential estates as the fight against crime intensifies.

"As we promised before, the war against organized crime will be intensified until all criminals are eliminated in this country. We will not rest until security situation returns to normal," Ndegwa said by telephone.

He warned that the crackdown on the rising insecurity in the country would continue to bring to end politically-linked criminal gangs causing panic ahead of this year's general elections.

Ndegwa said the police recovered several rounds of ammunitions, mobile phones and toy pistols during the crackdown on the criminals.

Police launched a crackdown mid this year after two policemen were killed and several headless bodies were recovered in Nairobi slums and other Mungiki bastions in central Kenya.

Thousands suspected Mungiki sect members, said to have its origins in the Mau Mau uprising of the 1950s against former colonial powers, have been apprehended in the central and Nairobi provinces since the start of the year.

Dozens of criminals without links to the sect have also been killed by police forces on high alert across Kenya.

The latest killings come as human rights groups called for urgent action over escalating insecurity in the country, saying the vice has reached "a national security crisis."

The Kenya Human Rights Network also petitioned the state body, Kenya National Commission of Human Rights (KNCHR), to establish a public inquiry into the security crisis tribal clashes in various parts of the country.

The activists said 300 criminals, police officers, victims of land clashes and suspected members of a banned sect were killed in the last six months alone.

The latest violence has set off an acrimonious debate, with critics accusing some politicians of exploiting the country's jobless youth to spark unrest ahead of the elections.