<p>A deadly bombing on a packed trolleybus in the Russian city of Volgograd was caused by a male suicide bomber, investigators said today, as the official death toll rose to 14 people.<br /><br /></p>.<p>"The explosives were detonated by a male suicide bomber, fragments of whose body have been found," the Investigative Committee said, adding that the kind of explosive used showed the trolleybus attack and a deadly strike yesterday on Volgograd train station could have been jointly planned.<br /><br />Health ministry spokesman Oleg Salagai told Russian state television that 14 people were killed in the trolleybus bombing and 28 wounded.<br /><br />President Vladimir Putin ordered security stepped up across all of Russia after bombings, the national anti-terror committee announced.</p>
<p>A deadly bombing on a packed trolleybus in the Russian city of Volgograd was caused by a male suicide bomber, investigators said today, as the official death toll rose to 14 people.<br /><br /></p>.<p>"The explosives were detonated by a male suicide bomber, fragments of whose body have been found," the Investigative Committee said, adding that the kind of explosive used showed the trolleybus attack and a deadly strike yesterday on Volgograd train station could have been jointly planned.<br /><br />Health ministry spokesman Oleg Salagai told Russian state television that 14 people were killed in the trolleybus bombing and 28 wounded.<br /><br />President Vladimir Putin ordered security stepped up across all of Russia after bombings, the national anti-terror committee announced.</p>