Garissa - Days after Islamists killed 148 people at Garissa university, Kenya's president held out an olive branch to Muslims and urged them to join Nairobi in the struggle against militant Islam by informing on sympathisers.But as Uhuru Kenyatta launches a battle for Muslim hearts and minds, his security forces must first reckon with the deep mistrust among ethnic-Somali Muslims in the country's northeast regions bordering Somalia.Kenyatta also faces an uphill task in reforming the violent ways of troops on the ground. A day before he spoke, a soldier in Garissa was seen by a Reuters reporter lashing at a crowd of Muslim women with a long stick."We live in fear," said Barey Bare, one of a dozen veiled Somali-Kenyan women targeted by the soldier."The military are a threat and al-Shabaab are a threat. We are in between."Without the co-operation of local people like Bare, experts say Kenya will struggle to glean vital on-the-ground intelligence to stop crude but highly lethal assaults by Somalia's al-Shabaab militants.Winning favour with Muslim communities near Somalia has been made more urgent by al Shabaab's switch in tactics to target Kenya's frontier regions near the porous 700km border. Al Shabaab has killed more than 400 people in two years, including 67 during an assault on Nairobi's Westgate mall in 2013."Kenyans can't afford to build a wall with Somalia so intelligence from local sources is the best approach. But people in villages won't inform if Kenyan soldiers steal or hit women," said one Western diplomat.Kenyan Defence Forces (KDF) spokesperson David Obonyo denied the troops had a track record of brutality against Muslims, who make up about 10% of Kenya's 44 million people."I don't see why we would harm our own citizens in Kenya. We are there to protect them," he said.Cripple intelligenceAnalysts and diplomats say Kenya's top brass are now aware heavy-handed security tactics can cripple intelligence gathering.Mass security sweeps also breed radicalisation and help al-Shabaab portray itself as the protector of Muslims in Kenya, Muslim groups say."In the upper echelons, especially in the intelligence department, there are constant warnings to police that these mass arrests are counter productive," said Rashid Abdi, a Horn of Africa security analyst.Though the group has lost swathes of territory and key sources of income in its native Somalia, it can still strike at soft targets in Kenya by using a handful of fighters with AK-47 rifles and grenades. Local knowledge also helps.One of the four fighters who stormed the Garissa college was an ethnic-Somali whose father was a Kenyan government official, intensifying fears about home-grown jihadis. Five other Kenyans have been arrested since."Radicalisation has grown and become a national problem rather than a regional problem," said Ali Roba, the governor of Mandera, a region also targeted by militants. Urging Muslims to do more to root out jihadi sympathisers within their community, Kenyatta said the attacks by the Somali militants threaten economic progress in their heartlands."I urge all my brothers and sisters in the affected regions, and across the country, to not allow those who hide and abet the terrorists to compromise and even destroy the development that is fast growing in your area," said Kenyatta, who replaced his intelligence and police chief following attacks.New methodsJoseph Nkaissery, appointed interior minister in December, has impressed diplomats with his desire to use more modern methods to counter radicalisation.But to get Muslims on board, especially the 2.4 million ethnic Somalis living in Kenya, the authorities will have to address their deep suspicion of the security services. Many say they carry extra "shake down" cash for bribes."Their interest is just money. You can't go to the government to complain, nothing will happen," said Saddam Hassan, 23, who had to pay a $216 bribe to be freed after four days in custody last April.Diplomats say coming months could be key to see if the new leadership whole-heartedly embraces a new strategy or reverts to bad old ways.Kenya's shutdown of Somali money transfer firms, vital to Somali businesses and people who rely on remittances from family members abroad, has raised concern.So has the closure of two coastal civil society groups that were mediating talks between the government and radicalised Muslim youths who had burnt down churches and attacked Christians in the Indian Ocean port city of Mombasa.In Nairobi's Eastleigh district, popularly known as Little Mogadishu, a change in policy is welcomed. But jaded by what civil society groups say is years of harassment, most ethnic-Somalis are bracing for another crackdown."We are tense because of the expectation of what's to come," said Ibrahim Ali Maalim, a local Imam.