Shi'ite Houthi rebels in Yemen have arrested more than 120 members of a rival Islamic Sunni party, even as a Houthi leader has proposed peace talks.
The Houthis raided homes and offices in the capital, Sana'a, rounding up members of the Islah party, which has ties to Egypt's Muslim Brotherhood. Islah also backs the Saudi-led coalition airstrikes against the Houthis.
The raids came as senior Houthi leader Saleh al-Sammad said the rebels are willing to hold peace talks if the Saudis stop the bombing.
Sammad told Reuters Sunday, "We have no conditions except a halt to the aggression......and any international or regional parties that have no aggressive positions toward the Yemeni people can oversee the dialogue."
There has been no reaction yet from the Yemeni government or any other rival parties. But previous United Nations efforts at mediation have failed.
The Houthis gained ground in the main southern city of Aden Sunday. The French News Agency reports the rebels took over the government headquarters, including the governor's office, in Aden's Mualla district.
Eyewitnesses said gun battles and heavy shelling ripped through a downtown district near the city's port.
It was not immediately clear how much territory the Houthis control.
Houthi tanks attempted to advance into Aden from the north, despite resistance from local fighters.
Arab media also reported tribal fighters from the eastern province of Hadramout are also trying to move on Makalla from the east to try to dislodge al-Qaida fighters who control the district. The Houthis also appear to be attempting to advance from the west.
The Houthis' al Maseera TV showed video of the port region of Aden, claiming the group controls the area. A young Houthi fighter in a military uniform insisted his unit is advancing, saying Houthi tanks are ready to move on the nearby district of Makalla.
Al Arabiya TV indicated the Saudi-led coalition battling to push back the Houthis launched airstrikes along various routes to try to cut Houthi supply lines.
Last Hadi stronghold
The Houthi forces have been battling to take Aden, a last foothold of fighters loyal to Saudi-backed President Abd-Rabbu Mansour Hadi, advancing to the city center despite 11 days of airstrikes by a Saudi-led coalition of mainly Gulf air forces.
Sunni Muslim Saudi Arabia launched the air strikes on March 26 in an attempt to turn back the Iran-allied Shi'ite Houthis, who already control Yemen's capital Sana'a, and restore some of Hadi's crumbling authority.
The fighting has failed so far to inflict any decisive defeat on the Houthis, who deny they are being armed by Tehran, or the supporters of former president Ali Abdullah Saleh, who are fighting alongside them, but the growing death toll and humanitarian suffering has alarmed aid workers.
The United Nations said on Thursday that more than 500 people had been killed in two weeks of fighting in Yemen.
The International Red Cross said Sunday it had been given permission by the Saudi-led coalition to enter Yeman with medical supplies and staff, a spokeswoman told Reuters.
Red Cross spokeswoman Sitara Jabeen tells VOA there is a "dire humanitarian situation" in the country. She says Yemen is running low on life-saving medicine and equipment. The fighting also has led to cutoffs of water and electricity, with aid workers reporting that Aden has been dry and dark for nearly three days.
A pro-Hadi militia source said 36 Houthi and allied fighters were killed on Sunday in Aden's central Mualla district, near the port, while 11 of Hadi's combatants died.
Ready for talks
Both Saudi Arabia and the Houthis say they are ready for talks which could return Yemen to the political transition which started when Saleh stood down in 2012 following huge street protests against his rule, inspired by wider Arab uprisings.
But they have set out incompatible conditions for the talks and neighboring Oman, which often steers an independent course in the Gulf and has stayed clear of the Saudi-led military operations, said last week that neither side was ready for negotiations.
A senior Houthi member said on Sunday the group is ready for peace talks as long as the Saudi-led air campaign is halted and negotiations are overseen by “non-aggressive” parties.
Some information for this report was provided by AP, AFP and Reuters.