Gunmen killed a Muslim cleric and three others in a hail of bullets in the Kenyan port city of Mombasa, a year after the imam's predecessor was killed in the same manner and on the same road and nearly the same spot.
The killings triggered street violence by youths on Friday who blamed police for the homicides, and four more people were killed in the mayhem.
The cleric's supporters alleged that the shooting death late Thursday of Sheik Ibrahim Ismael was a reprisal by Kenyan security forces for the September 21 attack on Nairobi's Westgate Mall that killed more than 60 people. A Somali Islamic extremist group, al-Shabab, claimed responsibility for the mall attack.
Ismael's predecessor at the Masjid Musa Mosque, who was gunned down in August 2012, had been accused of aiding al-Shabab, including recruiting youths for the Somali group.
"While it's possible the timing is linked, the pattern of targeted killings and disappearances in Mombasa long predates Westgate. What's clear is that a serious independent investigation of yesterday's killing and earlier attacks on Aboud Rogo and others is urgently needed to answer the many questions about these attacks," Leslie Lefkow, an Africa researcher at Human Rights Watch said.
The dark four-door car that Ismael was riding in was riddled by bullets. People gathered around the car, taking photographs and staring at the bodies as weeping relatives of the dead approached.
Police spokeswoman Gatiria Mboroki denied that police had any involvement in the killings. "We are investigating who did this and what the motive is because we don't know," she said.
Human rights groups estimate that Kenyan police were responsible for approximately 1,000 extrajudicial killings between 2008 and 2012, according to the US State Department.
"Members of the security forces were suspected of being responsible for a number of forced disappearances. At least half dozen prominent Muslim leaders alleged to have terrorist ties were victims of killings or forced disappearances," the State Department said, in its annual report on human rights.
Young men on Friday partly burned the Salvation Army Church and put burning tires on the road. Police carrying assault rifles came to the scene as smoke poured from the compound.
Police fired into the air and lobbed tear gas. Kenya's Red Cross said four people were killed in the rioting, including at least one with gunshot wounds.
Supporters who had gathered around the scene of Ismael's assassination Thursday blamed Kenyan police for the deaths, saying the killings were payback for the Westgate Mall attack in Nairobi.
"If we take up arms we are terrorists, if we don't we get killed ... what are we supposed to do when they are killing us. The police are killing us," said Sheik Abubaker Shariff Ahmed also known as Makaburi, who has been sanctioned by the United Nations and the US for alleged links to al-Shabab.
The four deaths and Friday violence come amid fears of worsening relations between Kenya's minority Muslim population - many of whom are of Somali origin - and Kenya's majority Christian population.
Ismael preached at Mombasa's Masjid Musa Mosque, where Aboud Rogo Mohammed once preached. Mohammed had been sanctioned by the UN and US for supporting al-Shabab. A Kenyan government task force did not establish who killed Mohammed. His supporters and human rights groups blamed the police. The killing led to days of deadly violence in Mombasa, which lies on the Indian Ocean and has a large Muslim population.
In the wake of Friday's violence, the US Embassy restricted travel to Mombasa and said "we strongly encourage all American citizens" to avoid areas in Mombasa where violence has been seen.
"There is the potential of further demonstrations and violence," the embassy said.
The UN advised its staff in Mombasa to minimise their movements and to follow a 10pm curfew over the weekend.
Following the Kenya mall attack, Human Rights Watch researcher Laetitia Bader wrote that many Somalis who have fled to Kenya because of al-Shabab violence inside Somalia have sometimes faced "serious abuses at the hands of the Kenyan security forces who wrongfully accuse them of supporting" al-Shabab.