A day of clashes between Shiite rebels and gunmen from the powerful Hashid tribe in northern Yemen have left 20 people dead, tribal sources said Wednesday.

Heavy fighting raged Tuesday in the towns of Wadi Khaywan and Usaimat, strongholds of the Hashid tribe in Amran province, before it receded on Wednesday as mediators made a new attempt to broker a ceasefire, a tribal source said.

“Clashes on Tuesday left 20 people dead from both sides,” the source said.