Boys play July 28, 2014 in front of a mural that calls for youth to live in peace in the swahili language in Nairobi's sprawling Kibera slum , a hotspot of deadly ethnic violence following the disputed results of the 2007 general elections
Nairobi (AFP) - Kenya takes pride in being a union of "42 tribes", but a string of attacks in towns on its volatile Indian Ocean coast has exposed bitter and explosive ethnic tensions linked to politics.
The series of killings in which around 100 people have died in recent weeks have provoked warlike political speeches, alarmist headlines, and offensive and inflammatory messages on social media.
"There has been a surge of dangerous speech," said 26-year-old Nanjira Sambuli, a project leader of Umati, an online project monitoring hate speech, based in Nairobi's sleek iHub offices.
The gruesome massacres near the tourist island of Lamu in June were claimed by the Shebab, Somalia's Al-Qaeda-linked insurgents, saying the murders were retaliation for Kenya's military role in their country.
But Kenyan President Uhuru Kenyatta has insisted the Shebab had nothing to do with it and instead blamed "local political networks" and ethnic hatred.
Kenya's media however saw him as pointing the finger at the main opposition, raising tensions further in a nation where political loyalties reflect ethnic differences.
- 'Worrying proportions' -
The attacks targeted areas settled decades ago by the Kikuyu, the same ethnic community as Kenyatta, who come traditionally from Kenya's central highlands.
Tensions are high on the coast, including an explosive mix of radical Islamists and separatists from the Mombasa Republican Council (MRC), a group that campaigns for independence for the majority-Muslim coastal region.
Messages on social media focus on "ethnicity", often using a "coded language" full of innuendo, Sambuli said, while adding there were also many online trying to counter or "neutralise hate speech".
The government has launched a campaign promoting the hashtag #StopHateSpeechKenya to push for an end to online abuse.
"The extent of hate speech and incitement has reached worrying proportions," said Mary Ombara, a senior information ministry official.
The national communications authority has warned radio and television stations against airing content that may divide the country along tribal lines.
Balancing reporting on attacks and ensuring that it does not inflame tensions further has Kenya journalists treading a tightrope.
Reporters have been criticised by fiercely partisan supporters of political leaders, most usually divided by tribe.
"It's been crazy," said Ferdinand Omondi, a reporter at one of Kenya's leading television stations KTN, who was criticised by some after the attacks because he had alluded to sensitive land disputes.
Politicians and activists have all been accused of running hate campaigns, while others raise the issues of free speech and censorship.
"Where's the dividing line between facts and hate speech?" asked opposition leader Raila Odinga, a former prime minister, in a recent interview with AFP.
"If, for example, you are saying that (government) appointments are not being done in a fair way -- there’s no equity and inclusivity in the appointments, you are stating a fact," he said.
Memories are still bitter of the ethnic clashes following 2007 elections, Kenya's worst unrest since independence.
Kenyatta and his deputy William Ruto are facing crimes against humanity trials for their alleged parts in that violence at the International Criminal Court.
The 2007-8 violence erupted when Odinga accused then president Mwai Kibaki of rigging his way to re-election. But what began as political riots quickly turned into ethnic killings of Kibaki's Kikuyu tribe, the country's largest single group.
Despite efforts to heal the wounds of the ethnic killings, tensions still run deep between communities, with many grievances that fed into the violence -- most notably land ownership rights and claims that minorities are being marginalised -- still unresolved.
- Tribe and politics linked -
Since the Lamu attacks, hate leaflets have been distributed warning specific ethnic groups to leave the area.
And the National Cohesion and Integration Commission, a body formed following the 2007-2008 violence, has been criticised for failing to prosecute perpetrators of hate speech.
"We are pushing for cyber-laws, because a lot of people still get away with it," said Ombara.
But activists such as Sambuli think such laws would do little, and that the authorities should rather "focus on figuring out the deeper issues".
With ethnic differences playing out in politics and online, they are also going on stage.
Renowned comedian Sammy Mwangi is preparing a stand-up comedy show about the stereotypes of the Luo community, a major ethnic group.
"As Kenyans, we generally don't care about the other person's tribe until politics creeps in," he said.
For Mwangi -- a Kikuyu preparing a comedy about the Luo, the country's third largest ethnic group -- laughter is the best remedy to tensions.
"With comedy, it doesn't matter whatever the language or tribe, it cuts through many barriers," Mwangi said.