Clashes between Yemeni troops and supporters of a dissident cleric are reported to be continuing, despite official claims that they had ended.
A $55,000 bounty is on offer for Hussein al-Houthi
Soldiers are still fighting militants loyal to Hussein al-Houthi, three days after an army chief said the resistance was all but overcome.
Reports of the numbers of rebels and soldiers killed in seven weeks of raids vary from about 80 to more than 600.
Sheikh al-Houthi is accused of setting up unlicensed religious centres.
He is also accused of forming an armed group which staged violent protests against the US and Israel.
Yemeni President Ali Abdullah Saleh has accused Mr Houthi and his supporters of being "foreign agents" seeking to foment sectarian strife.
'Crushed within hours'
Officials say the action is not aimed at Zaidis in general. Zaidis are members of a moderate Shia Muslim sect that is dominant in the region near the Saudi border in what is otherwise a mainly Sunni country.
Army chief of staff Brig Gen Mohammad al-Qassimi said on Friday that resistance to government forces in the mountainous region of Saada province, 240km (150 miles) north of the capital Sanaa was almost beaten.
"I can assure you it will be crushed within 12 hours," he told reporters.
Mr Houthi is believed to be hiding in the area.
A reward of about $55,000 has been offered for his capture, but President Saleh has promised a fair trial if he surrenders.