SANAA, Yemen (AP) -- Yemen's defiant president addressed his troubled nation Sunday for the first time since returning to the country after an assassination attempt, making no promise to immediately step down but saying he is committed to a deal to end months of spiraling violence.

Ali Abdullah Saleh appeared in improved health after nearly four months of treatment in neighboring Saudi Arabia for severe burns and other injuries he suffered in a June 3 attack on his compound in Yemen's capital, Sanaa. Saleh abruptly returned on Friday, and a week of renewed clashes with his opponents intensified, littering the streets of the capital with bodies.

``The crisis is big. You who are chasing power, let's all go to the ballot boxes,'' Saleh said, speaking to his opponents and suggesting elections rather than agreeing to step down.

Yemen's autocratic ruler of 33 years is under tremendous pressure from street protesters and neighboring Arab nations to transfer power to end the country's deepening crisis, which has killed hundreds since anti-government demonstrations began in February, ignited by the unrest sweeping the Arab world.

He has signaled an intention several times to sign a U.S.-backed deal to step aside in exchange for immunity from prosecution only to back out at the last minute.

In Sunday's televised address, he said he was committed to the deal, which was drafted by an alliance of Gulf nations that includes powerful Saudi Arabia.

His opponents, however, do not trust him and believe he is stalling for time while consolidating his hold on power. Saleh has tasked his vice president with overseeing negotiations on the deal, but at no point in his address did he provide any indication he might agree to demands to step down immediately.

Opposition spokesman Mohammed al-Sabri said ``Saleh gave a speech full of contradictions.''

``There are very clear demands for Saleh: cease violence, quickly transfer power and sign the deal,'' he said.

Over the past week, Saleh's forces have unleashed heavy shelling on renegade army troops and protesters who have held a sit-in since February at a plaza in the capital they dubbed Change Square. Around 150 people have been killed in the renewed fighting. Armed anti-government tribesmen are also involved in the battles.

A committee of tribal leaders and military officials set up to mediate a pullback of forces by both sides has not received a green light from Saleh to start its work, a military official said Sunday, speaking on condition of anonymity because he was barred from releasing information.

Military transport trucks were still pouring soldiers into the streets.

Yemen's turmoil is of enormous concern to the United States and Europe because the country has become a haven for Islamic militants, including al-Qaida in the Arabian Peninsula, which Washington says is the most dangerous remnant of the global terror network.

Al-Qaida-linked fighters have already taken advantage of the unrest to overrun several towns in southern Yemen, expanding their range of influence beyond Yemen's remote hinterlands.

Saleh accused his opponents of cooperating with al-Qaida, plotting a coup and shedding blood in an attempt to seize power.

``Al-Qaida is completely supported by the outlaw elements who are against constitutional legitimacy,'' he said. ``They supplied them (al-Qaida) with information and financial and military support.''

In turn, the opposition and some elements in the security establishment have accused Saleh of allowing al-Qaida-linked fighters to take over the southern towns to heighten fears in the West. Saleh himself has made the argument many times that without him in power, Islamic militants would seize the whole country.

Saleh insisted on taking the country to early presidential and parliamentary elections. But under the Gulf-mediated power-transfer deal, Saleh would have to step down first.

He also hinted at the possibility of returning to the Saudi kingdom ``to continue treatment and recuperating in the coming months.''

At times, the address was conciliatory, putting his words in sharp contrast with the increased bloodshed in the streets over the past week, which has included pro-government snipers firing on unarmed protesters.

Outside Sanaa, violence flared in the mountainous villages of Arhab, a stronghold of northern anti-Saleh tribes. Republican Guard forces shelled the villages in the early morning, killing two people and wounding six, according to tribal sheik Hamid Assem.

In the southern city of Taiz, which has witnessed mass protests for the past months, one soldier and one tribesman were killed when fighters attacked security forces in retaliation for the bombing of the house of an anti-Saleh tribal leader.

Hours before he spoke, Saleh's forces opened fire on protesters in the heart of Sanaa, injuring at least 18 people. A day earlier, Yemen witnessed one of the bloodiest days of the uprising as Saleh's forces waged attacks on protesters and a renegade army unit protecting them, killing more than 40 people.

The spike in violence appeared to signal an attempt by Saleh to crush his rivals and tighten his grip on the country after his surprise return from Saudi Arabia.