Hand-held radios used by Hezbollah detonated late on Wednesday afternoon across Lebanon’s south and in Beirut’s southern suburbs, a security source and a witness said, further hiking tensions with Israel a day after similar explosions launched via the group’s pagers.

At least one of the blasts took place near a funeral organized by Iran-backed Hezbollah for those killed the previous day when thousands of pagers used by the group exploded across the country and wounded many of the group’s fighters.

The group, which was thrown briefly into disarray by the pager attacks, said on Wednesday it had attacked Israeli artillery positions with rockets in the first strike at its arch-foe since blasts wounded thousands of its members in Lebanon and raised the prospect of a wider Middle East war.

The hand-held radios were purchased by Hezbollah five months ago, around the same time that the pagers were bought, said a security source.

Israel’s spy agency Mossad, which has a long history of sophisticated operations on foreign soil, planted explosives inside pagers imported by Hezbollah months before Tuesday’s detonations, a senior Lebanese security source and another source told Reuters.

The death toll rose to 12, including two children, Lebanese Health Minister Firass Abiad said on Wednesday. Tuesday’s attack wounded nearly 3,000 people, including many of the militant group’s fighters and Iran’s envoy to Beirut.