BEIRUT — New explosions linked to electronic devices killed at least 20 people and injured more than 450 across Lebanon on Wednesday, a day after 12 people were killed and thousands wounded by exploding pagers used by members of the militant group Hezbollah in a suspected Israeli attack.

       The source of Wednesday’s explosions was not immediately clear. The state news agency said some of the explosions occurred in a brand of two-way radio. At least one of the explosions occurred at a funeral in Beirut’s southern suburbs, held by Hezbollah for people who were killed in Tuesday’s blasts.