Dhaka, March 19 -- A cross-border drone attack from Sudan killed 17 people in Chad including mourners attending a funeral service, the Chadian government and local sources said on Thursday, and the country's president vowed to retaliate for any further attacks.

The border town of Tine was struck on Wednesday afternoon as mourners gathered at a house for a funeral ceremony for a dead relative that involved reading the Koran, a local resident said.

There were two explosions and casualties included mourners and children who had been playing nearby, said the resident, who declined to be identified for security reasons.

Local government sources said it was not immediately clear who was behind the attack.

The conflict in Sudan between the S...