Oil prices rallied for a second straight day yesterday after Saudi Arabia and its Gulf Arab allies began air strikes in Yemen, sparking fears of a bigger Middle East battle that could disrupt world crude supplies.

Suicide bombers in the Yemeni capital Sanaa blew themselves up during Friday prayers at two mosques used by supporters of Shi’ite rebels, killing 142 people and wounding 260 in the country’s deadliest militant attack in years.

Thousands of protesters have demonstrated across Yemen, some supporting the Shiite rebels who seized the capital and others demanding the country’s south secede after the nation’s president and cabinet resigned.