Lebanese police say one person was hurt when two hand grenades exploded in two neighborhoods of Beirut overnight in renewed tensions sparked by the weekend death of a demonstrator. Police say unknown attackers hurled a grenade on a road underpass in the Shi'ite-populated south Beirut suburb of Tayyouneh early Tuesday. Another grenade exploded near a cafe in the south Beirut suburb of Jnah, injuring one. Tensions shot up after a Druse demonstrator was stabbed to death as he left a Saturday rally marking the 2005 assassination of former Premier Rafik Hariri. Enraged Druse attacked minivans carrying Shi'ites in central Lebanon, injuring two. Sectarian tensions last year erupted into clashes that put Lebanon on the verge of another civil war.