Yemeni President Ali Abdullah Saleh has arrived in the United States for short-term visit to receive medical treatment.

Saleh arrived at an unspecified location in the United States on Saturday after a journey that took him from Oman, through London.

The one-line Yemeni statement said Saleh was in the US for a "short-term private medical visit."

Saleh's travel plans in the United States have not been disclosed for security reasons. It wasn't clear how long he intends to remain in the US, where he intended to stay while in the country, or where he would be receiving medical care.

Saleh has transferred some powers to his deputy and enjoys immunity from prosecution under a deal meant to end increasing instability in Yemen.

The deal also established a transitional government including the opposition and envisions restructuring Yemen's
armed forces, key units of which are led by Saleh's relatives.

The US, which endorsed the plan to coax Saleh out of office by granting him immunity from prosecution over the
deaths of protesters, had defended its decision to issue him a visa, despite criticism that it would be seen as sheltering him.

Saleh had originally been expected to stop only briefly in Oman after leaving the Yemeni capital Sanaa last Sunday. He had said in a parting speech he would return to Yemen.

A foreign diplomat in Oman said, however, that Saleh had sought permission to reside there. An Omani government s

ource declined to confirm or deny receiving such a request, but said Oman would be reluctant to agree to it in case this harmed future ties with Yemen.

Oil route threatened

The US and Saudi Arabia fear a protracted political upheaval in Yemen could give al-Qaeda's regional wing a foothold
near oil shipping routes through the Red Sea.

Underlining the continued violence, Yemeni troops killed four Islamist fighters in the southern town of Zinjibar, a local
official said on Saturday.

He said the four fighters from Ansar al-Shariah were killed in a skirmish on the eastern edge of Zinjibar, which Islamists
fighters overran last May. One soldier was killed in the fighting late on Friday, he said.

A spokesman for the Islamist group said his side had suffered no casualties, but confirmed the account of a soldier's
death.

Saleh's foes accuse him of deliberately ceding territory to Islamists to make himself indispensable to his former US
patrons, and of ultimately aiming to sabotage the political transition and retain power for his inner circle.