The spokesman for Yemen's Shi'ite rebels said Saudi fighter jets have bombed the group's northern stronghold a day after Saudi Arabia accused the fighters of killing a soldier in a border skirmish.

The northern rebels, known as Hawthis, have been battling Yemeni government forces intensively over the past few months in the latest flare-up of a sporadic conflict over the last five years. The Hawthis are based in a northern province that borders Saudi Arabia.

Hawthi spokesman Mohammed Abdel-Salam told The Associated Press the Saudi offensive early Thursday hit at least four areas inside Yemeni territory. There was no immediate word on casualties.

Saudi and Yemeni government officials could not immediately be reached for comment.