ADEN/WASHINGTON: Yemen’s President Ali Abdullah Saleh was so severely injured in an assassination attempt that it is uncertain when he will return, Yemen Vice President Abd-Rabbu Mansour Hadi has said.

Saleh was injured in an attack on his palace in early June and is receiving medical treatment in Saudi Arabia. Yemen has been shaken by months of protests against his three-decade rule.

In fresh fighting overnight in southern Yemen, Islamist militants linked with Al-Qaeda killed five Yemeni soldiers trying to retake control of a vital football stadium seized by the insurgents Wednesday, a local official said.

Hadi told CNN in an interview that he saw Saleh immediately after the bomb attack and the Yemeni leader had a piece of wood between his ribs in his chest and burns to his face, arms and upper body.

Hadi said according to the doctors no one can tell when Saleh might return.

“Days, weeks, months,” he told CNN. “It could be months, this is a decision up to the doctors.”

Opposition officials meanwhile said that more than 300 government soldiers had defected, in a further blow to Saleh as he recovers from his injuries.

In a message sent through his foreign minister on state television Wednesday, Saleh called for dialogue with the opposition to implement a Gulf-brokered plan for a transfer of power.

“We discussed the Gulf initiative, and [Saleh] called for the opening of a dialogue with the opposition … in order to agree on a vehicle by which to implement the Gulf initiative,” Yemen’s Foreign Minister Abubakr al-Qirbi said.

Qirbi said he had visited Saleh in hospital and that his health and that of other high ranking officials who were injured in the attack was “good and in continuous improvement.”

Yemeni officials had said Saleh would make his first public appearance since the palace attack this week but Saleh’s media secretary Ahmad al-Sufi told Reuters the president’s plan to record a video message to be broadcast on state television had been delayed on the advice of his doctors.

Yemen, the poorest Arab state and a neighbor of the world’s largest oil exporter Saudi Arabia, has been shaken by the protests against Saleh, a resurgent wing of Al-Qaeda and a separatist rebellion in the south.

The United States and Saudi Arabia fear Al-Qaeda may use the chaos to launch attacks in the region and beyond.

A local Yemeni official said Thursday that one militant was also killed in the fighting around the stadium, which the insurgents seized Wednesday in heavy fighting that killed at least 26 government soldiers. At least 18 insurgents also died.

Militants also pressed against a military base housing the 25 Mechanized Division, deployed to fight the militants in Zinjibar, raising fears the militants may next target Aden, Yemen’s second largest city and home of the country’s main oil refinery.

Yemeni officials had been reporting successes against the estimated 300 militants who seized control of Zinjibar in May in the midst of a groundswell of popular protests against Saleh.

Opposition officials reported that more than 300 members of the Yemeni security forces, including 150 from the Republican Guards led by Saleh’s son Ahmad, had defected to rebels.

“From the podium of the Square of Change in Sanaa, an announcement has been issued that 150 soldiers from the Republican Guards, 130 Central Security soldiers and 60 policemen have joined the revolt,” an opposition message said.

Government officials were unavailable for a comment.

There have been a series of defections by security forces since the anti-Saleh uprising began in February. Most prominent has since sent in his troops to guard protesters in Sanaa.

Yemen has been quiet with a cease-fire in place since Saleh was injured in the attack, which investigators say was caused by explosives planted in the palace mosque where he and senior government officials were praying

Saleh, 69, who has not been seen in public since the attack, has resisted pressure from the United States and Saudi Arabia to handover power to his deputy, Abd-Rabbu Mansour Hadi, under a Gulf nations’ initiative to end the crisis.

Hadi has been running the country in Saleh’s absence but the opposition is demanding a formal hand over of power to pave the way for new elections.