Shelling and explosions rocked several Syrian cities early Thursday, leaving at least eight dead, a day after a high-ranking official apparently resigned to join the uprising.

A man identifying himself as Abdo Hussam el Din, the country's deputy oil minister, announced in a video posted on YouTube on Wednesday that he was defecting from the regime of President Bashar al-Assad.

"I am joining the revolution of this noble people who will not accept injustice," the man said in Arabic. "I've been part of this government for 33 years, and I have acquired many titles, and I do not want to retire serving the crimes of this regime."