Yemeni government forces have killed at least six civilians in Taiz, the country's second largest city.

Medical officials and witnesses say the civilians were killed early Friday after forces renewed shelling in Taiz, where protesters have been calling for President Ali Abdullah Saleh's departure.

They say a government raid in the city on Thursday left one person dead.

The deadly violence has coincided with a visit by a U.N. envoy who arrived Thursday in Yemen to try to convince Mr. Saleh to accept an initiative that calls for him to hand over power.

The Yemeni leader has indicated on several occasions that he would accept the terms of the agreement, which was brokered by the Gulf Cooperation Council . However, each time he has backed away without signing the plan.

For months, opposition activists have held demonstrations calling on Mr. Saleh to resign. The president's supporters frequently have held rival rallies coinciding with the opposition protests.

Mr. Saleh could face increased pressure from the European Union next week to accept the GCC initiative. French Foreign Minister Alain Juppe says the EU is set to discuss a plan that would freeze Mr. Saleh's assets if he does not agree to end his 33-year rule.