An opposition spokesman says an agreement has been reached with the acting president to begin discussions on how to transfer power from Yemen's President Ali Abdullah Saleh.
The spokesman, Abdullah Oubal, said the agreement was struck in a meeting Monday between acting president Abed Rabbo Mansour Hadi and opposition leaders.
In the capital Sanaa, however, witnesses said troops loyal and opposed to Saleh have been significantly reinforced, with more checkpoints and plainclothes gunmen visible on the streets.
Hadi's meeting with the opposition is the first since Saleh, Yemen's leader of nearly 33 years, left for Saudi Arabia on June 5 for treatment of wounds he suffered in a rocket attack on his Sanaa compound.
Saleh had faced months of nationwide protests calling for his ouster.