Suspected terrorists threw a grenade inside a church in Kenya’s capital Nairobi on Sunday, leaving at least one child killed and three people injured, police confirmed.Regional police commander, Moses Ombati told Xinhua that so far at least one child has been confirmed dead and 3 others injured in the attack at St. Polycarp Church along Juja road in Nairobi."The grenade attack occurred at around 10:30 a.m. when a suspected terrorist threw a grenade from a certain building near the church that targeted children who were in a Sunday school. One child was killed and we have rushed 3 others who were injured to the hospital,” Ombati told Xinhua.Police have launched a major manhunt for suspected terrorist who hurled a grenade into the church.Ombati said the police have launched investigations to establish the motive behind the attack which comes two months after 17 people were killed and more than 70 others injured in twin church grenade attacks in northern Kenya. The police have not established where the attackers came from since they hurled grenades that targeted children who were in the Sunday school. Kenya has seen several hit-and-run grenade attacks in recent months in the capital, Nairobi, and in northern Kenya and Mombasa port city.The Kenyan authorities often blame such attacks on al Qaida- affiliated Al-Shabaab rebels from neighbouring Somalia.The East African nation launched cross border incursion into Somalia last October in pursuit of the militants blamed for a series of grenade and landmine attacks in Nairobi, Mombasa and northern region. The authorities have called on Kenyans to be vigilant over terror attacks because of higher numbers of foreign fighters who sneaked into the country from neighboring Somalia who are fleeing military airstrikes by Kenya and Somali forces. Two days after Kenyan troops in the UN-backed African Union peacekeeping mission (AMISOM) captured the strategic port city of Kismayo, the insurgents have vowed to step up retaliatory attacks in Kenyan cities.Security in key towns in Kenya has been put on a high alert as Kenya’s soldiers prepare to launch a major onslaught on a strategic port city of Kismayo, a the base for revenue collection for the militia and major operations command base.