QUETTA, Pakistan (Reuters) - A suicide bomber killed a senior Pakistani police official on his way to work and two others on Thursday in the restive southwestern province of Baluchistan, officials said. Baluchistan was rocked by a series of attacks late last year that claimed over 180 lives and raised concerns about a growing militant presence, including fighters affiliated with Islamic State, which has claimed several bombings in the province.  The violence has raised concerns about security for projects in the $57 billion China Pakistan Economic Corridor, a planned transport and energy link from western China to Pakistan s southern deep-water port of Gwadar.  Three individuals have embraced martyrdom including (Additional Inspector General) Hamid Shakeel and his driver,  provincial government spokesman Anwar Ul Haq Kakar told Reuters.  A spokesman for the Tehreek-e-Taliban, also known as the Pakistani Taliban, claimed responsibility for the attack.  Shakil was on his way to work in the provincial capital, Quetta, when the suicide bomber intercepted his vehicle, Baluchistan police Inspector General Moazzam Jah told Reuters. One other police officer was killed and three officials were seriously wounded, he added.  Attacks on security officials in Baluchistan have accelerated, with four suicide bombings and one armed attack targeting police in the past six months.  