Several hundred gunmen attacked the Yemeni town of Houta on Wednesday and briefly seized control of parts of the southern town as they fought with security forces.

The armed group, which is suspected of including al-Qaida members, launched the attack before dawn. Witnesses and medics say two police officers were killed and at least three wounded in the fighting.

The attack raises concerns of increased violence from militant groups nationwide in the wake of anti-government protests and the absence of President Ali Abdullah Saleh. Militants seized two other southern cities in May.

President Saleh is recuperating in Saudi Arabia from injuries sustained in a bomb attack on his presidential compound earlier this month. Yemen's state-run SABA news agency says the president stated that his health was improving on Wednesday as he spoke by phone to Saudi government officials.

On Tuesday, hundreds of thousands of Yemenis rallied in major cities throughout the country, demanding that Mr. Saleh step down. Protesters called for a transitional council that excludes members of the current government.

In the capital, Sana'a, a huge crowd swelled outside the home of Yemen's acting leader, Vice President Abd al-Rab Mansur Hadi — a day after Yemen's political opposition held talks with him on a possible transition plan.