US fears Yemen instability could impact war on terror (VIDEO)

Defense Secretary Robert Gates said on Tuesday that the U.S. was concerned about instability in Yemen, a day after top military leaders defected to the side of opposition protesters, prompting President Ali Abdullah Saleh to warn of a looming civil war.

Saleh, who fired his entire Cabinet on Sunday preempting what one government official said was a planned mass resignation, on Tuesday warned military leaders in a nationally televised address that any attempt at a coup would lead to civil war, VOA reported.

A wave of government officials, tribal leaders and diplomats have defected since gunmen loyal to Saleh, who has ruled Yemen for 32 years, opened fire on a group of protesters Friday, killing 52 people.

Maj.-Gen. Mohsen al-Ahmar was among several military leaders to defected Monday, after deploying thousands of soldiers to protect protesters who have been calling for the president to step down. He said he would "support the peaceful revolution."

Saleh, a U.S. ally in the fight against al Qaeda, has promised to step down from office at the end of his term in 2013, and offered dialogue with opposition leaders on a new constitution, but activists have rejected the offers.

Gates, while expressing concern about the impact of instability in Yemen on the fight against terrorism, declined to say whether Saleh should step down, Reuters reported.

He said: "I don't think it's my place to talk about internal affairs in Yemen."

He added that the U.S. considered the Yemen-based Al Qaeda in the Arabian Peninsula (AQAP) as perhaps the terror group's most-dangerous affiliate.

"And so instability and diversion of attention from dealing with AQAP is my primary concern about the situation," he said.