Policemen charge at rioting youths during protests by youths in the Kenyan coastal town of Mombasa August 28, 2012. [Photo/Agencies]

NAIROBI - Kenyan police on Tuesday blamed al Qaida-allied terror group, Al-Shabaab, for the murder of the fiery Islamic preacher Aboud Rogo in the coastal city of Mombasa on Monday.

Deputy Police spokesman Charles Owino said the manner in which violent street protests have been conducted and the swiftness in their hurling grenades at police officers trying to quell the mayhem shows that the Somali insurgents were blamed for it.

"If you look at the way things are happening including the use of grenades, ...... it shows that the killing was well planned," Owino told Xinhua by telephone late on Tuesday.

The Al-Shabaab fighters have been responsible for a string of foreigners' abductions and grenade attacks that occurred late last year that led to the Kenyan troops' pursuit of the militia group into Somalia.

The militia group is very angry with Kenya for sending troops into Somalia to attack its compounds and kill its fighters, but Nairobi said its military action in Somalia is only for self defense.

Kenya also blames Al-Shabaab for the recent kidnappings of four foreigners, and fears its tourism and business economy will be destroyed if it allows the insurgents to go on unchallenged.

Owino said Rogo had been accused before of taking part during the bombings of the U.S. embassy in Nairobi in 1998 and in the Kikambala terrorist attack against Israeli tourists 12 years ago but the police did not kill him.

"The police have been fighting Al-Shabaab for some time now. We have been arresting Rogo and arraigning him in court. If the police wanted to kill him, they would have done so long time ago and why now," the deputy police spokesman asked.

He said the murder of the terror suspect in broad daylight might have been committed by either his opponents or people who wanted to cause chaos in the coastal city.

"Just ask yourself why someone would burn churches in protests and why the police have not used firearms. Why did Rogo who claimed to have been trailed for several times not even pick registration number of the vehicles which were trailing him," Owino asked.

He said Rogo's murder seemed to have been well planned long time by people who wanted to cause chaos in Mombasa as it came barely a week after the deceased had incited the youth at one of the mosques in the port city.

The new development came as police are holding 14 suspects in connection with the violent demonstrations which have paralyzed business activities in the tourism-resort city.

The rowdy youths are protesting the killing of radical cleric who has been accused by the UN and U.S. for supporting Al-Shabaab militia to carry out bomb and grenade attacks in the east Africa region.

The pro-Rogo protesters invaded churches, looted property and set ablaze a Salvation Army church in Majengo in Mombasa.

"Some innocent people have been injured and some killed. We urge the government to send security forces to Mombasa to help restore normalcy," Mohammed Osman told Xinhua in Mombasa on Tuesday.

Earlier, a prison warder succumbed to injuries while after a grenade was hurled to him and his colleagues, moments after they alighted at a chaotic area in Kisauni, Mombasa.

At least 14 other security officers have been seriously injured and rushed to hospitals in the town, after the attack.

Regional police commander, Aggrey Adoli, said the group had gone to quell chaos that had rocked Mwandoni area, after a PCEA church was burnt by rowdy youths in the area.

"The officers were alighting from the lorry when someone maliciously hurled a hand grenade into the vehicle, thus injuring 14 of them, as we are speaking it is quite unfortunate that one of the prison warders passed on," said Adoli during a media briefing in Mombasa.

Security has been beefed up in most parts of the town, with churches, hotels, business establishments, among other areas, increasing their security.

Adoli said if things spiral out of hand, a curfew in Kisauni area might be imposed, but added that the Provincial Security Committee will sit and deliberate on the possibility of a curfew.

"The situation as it is now does not warrant a curfew, but if things change, we shall have to think about that. It is only the chairman of the committee, who can make such a decision after consultations," Adoli said.

The official added the incident cannot deter the officers from continuing with the operation to make Mombasa safe.

"We shall still continue with the operation, so that we can root out all bad elements. We have realized these are not normal criminals, they have ulterior motives," said Adoli.

He also revealed the officers had changed strategy and had made all arrangements to ensure they crack them down.

"The world has known they are terrorists bent to destroy our economy, not people with good motives," he said.

Some police officers, journalists and several other relief officials were repulsed by angry youths at Mlalelo area as they rushed to the scene of the church.

The group retreated to Dog Section area, where they waited for reinforcement as the youths also barricade the road.

Security has also been beefed up in beach hotels, airport and the port, with extra screening being conducted to anyone leaving or entering the areas.

The UN and U.S. placed Rogo on a sanctions list last month for allegedly recruiting fighters and raising money for the militant group.

The UN Security Council placed its own travel ban and assets- freeze on the cleric, saying he used an extremist group, Al Hijra, as a way of recruiting Swahili-speaking Africans to fight in Somalia.