Yemeni President Ali Abdullah Saleh has promised to leave his country for the United States, hours after security forces loyal to him shot and killed nine opposition protesters taking part in a giant march to the presidential compound.

In a news conference Saturday, Mr. Saleh said he will travel to the United States in the “coming days” to “get away” from media attention and allow the country's unity government to prepare for a February election to replace him. He also vowed to return to Yemen to pursue political work as an opposition figure. Mr. Saleh did not give any dates for his planned travels.

Earlier Saturday, Yemeni troops opened fire to stop the march by tens of thousands of anti-government activists who reached Sana'a after a four-day journey from the city of Taiz, 270 kilometers to the south. Soldiers and police also fired tear gas and used water cannon to block the marchers in the southern part of the capital. Medics say more than 200 people were wounded, many by gunfire.

Many Sana'a residents joined the arriving protesters, who want Mr. Saleh to stand trial for the killings of hundreds of activists during the government's efforts to suppress 10 months of opposition demonstrations.

Mr. Saleh has responded to the protests by agreeing to end his 33-year presidency after the February election — a deal backed by Gulf nations and Yemen's ruling and opposition parties. The agreement calls for all parties to back his deputy as the sole candidate in the election. Mr. Saleh also would be granted immunity from prosecution.

Many activists in Saturday's march chanted, “No immunity for Saleh.”

Meanwhile, Yemeni officials say unidentified gunmen killed a British citizen of Yemeni origin and wounded a security officer in a shooting on an oil company vehicle in the southern province of Hadramout on Saturday. One official blamed the attack on highway robbers.