Yemen¡¯s ?Houthis said they fired ballistic missiles at a Saudi oil tanker in the Red Sea, stepping up enforcement of a newly declared maritime blockade of Saudi Arabia.

The ?Iran-aligned group¡¯s military spokesperson, Yahya Saree, said ?the ?vessel had breached the blockade, ignored ?warning calls and was forced to change course.

Separately, the United Kingdom Maritime Trade Operations agency said ?on Tuesday that the master of a tanker ?had reported hearing an explosion while transiting the southern Red Sea.

UKMTO said the ?crew and vessel ?were safe and that no environmental damage had been reported. It could ?not be immediately verified??whether the advisory was related ?to the incident reported by the Houthis.

The Houthis ?said ?on July 20 they would impose a naval blockade on Saudi Arabia in the Red Sea in response to what they described ?as a Saudi siege on Yemen, an allegation Riyadh has denied.

The Saudi-led coalition in Yemen said it carried out strikes on Houthi military sites ?in ?Yemen¡¯s Hodeidah governorate on Friday, saying the ?sites were used to threaten commercial shipping.

The Houthis ?subsequently fired on Saudi oil installations in two ports on the Red Sea coast on Saturday, and Saudi-backed forces bombed the Houthis, ?as the war in the Persian Gulf that has disrupted global supplies extended to a second front.