SAN'A, Yemen - President Ali Abdullah Saleh was wounded when rebellious tribesmen struck his palace with rockets Friday, targeting him for the first time in a dramatic escalation of fighting that has turned parts of the capital into a battleground and pushed Yemen toward civil war.

One of the rockets smashed into a mosque on the palace grounds where Saleh was praying along with his top leadership. It was a stunning hit on the regime's most senior figures: Among the nine wounded were the prime minister, Saleh's powerful top security adviser, and the two heads of parliament, as well as the cleric leading prayers. Seven guards were killed.

Officials said Saleh had only slight injuries - Deputy Information Minister Abdu al-Janadi spoke only of "scratches to his face." But there were indications the injuries may have been more severe. Saleh, in his late 60s, was taken to a Defense Ministry hospital, while officials repeatedly promised he would soon appear in public. By late Friday, state TV had aired only an audio message from Saleh, with an old still photo.

"If you are well, I am well," the president said in the brief message, addressing Yemenis. He spoke in a labored voice, his breathing at times heavy. He blamed "this armed gang of outlaws" - the tribal fighters - for the attack and called on "all sons of the military around the country to confront" them.

The bold assault directly on the president is likely to heighten what has been an increasingly brutal fight between Saleh's forces and the heavily armed tribesmen loyal to Sheikh Sadeq al-Ahmar.

Since violence erupted May 23, San'a residents have been hiding in basements as the two sides fight over control of government ministries and duke it out with artillery and gun battles.

The bloodshed comes as nearly four months of protests and international diplomacy have failed to oust Yemen's leader of 33 years.

After the rocket attack, government forces intensified shelling on the capital's Hassaba district, the epicenter of the fighting where Ahmar's residential compound is located. Many of the compound's buildings and surrounding houses have already been heavily damaged.

The White House called on all sides to stop the fighting, which has killed more than 160 people. "Violence cannot resolve the issues that confront Yemen," press secretary Jay Carney said in a statement.

President Obama's homeland security and counterterrorism adviser, John Brennan, discussed the crisis in Yemen with officials in Saudi Arabia and the United Arab Emirates during a three-day visit to the gulf that ended Friday, vowing to work with Yemen's powerful neighbors to stop the violence.

Washington fears the chaos will undermine the Yemen government's U.S.-backed campaign against al-Qaeda's branch in the country, which has attempted a number of attacks against the United States. Saleh has been a crucial U.S. ally in the antiterror fight, but Washington is now trying to negotiate a stable exit for him.

Inspired by uprisings in Egypt and Tunisia, protesters have been trying unsuccessfully since February to oust Saleh with peaceful protests that have brought out hundreds of thousands daily in San'a and other cities.

Now the crisis has transformed into a power struggle between two of Yemen's most powerful families: Saleh's, which dominates the security forces, and the Ahmar clan, which leads the strongest tribal confederation, the Hashid.

Ahmar announced the Hashid's support for the protest movement in March, and his fighters adhered to the movement's nonviolence policy. But last week, Saleh's forces moved against Ahmar's residence in San'a, and the tribe's fighters rose up in fury.