Yemeni officials and clerics are criticising calls for Yemeni youth to fight alongside Jabhat al-Nusra (JAN) and other extremist opposition groups in Syria in the name of "jihad".
This will cause negative repercussions for Yemen and the region as a whole, they said.
One such call came in January, when Yemeni Sheikh Abdul Majeed al-Zindani of the country's Al-Islah Party issued a fatwa that sanctions jihad in Syria and urges neighbouring countries to open their borders to "mujahideen".
Yemeni newspapers and websites, including Al-Shareh and Al-Jumhour, have published reports indicating that religious leaders affiliated with Al-Islah recruited thousands of Yemenis and organised their travel through Turkey to Syria so they can fight with armed groups.
According to Interior Ministry spokesman Brig. Gen. Mohammed al-Qaedi, the government lacks "specific figures" regarding the number of recruits going to Syria.
Al-Qaedi called on Yemenis to focus on helping their own country.
"Yemenis must work together to lift the country out of its crisis because we have serious problems that require unity," said official ministry spokesman Brig. Gen. Mohammed al-Qaedi.
"All we can do is pray for our bothers in Syria so they can get out of the current situation in which they live," he added.
According to al-Qaedi, Yemen is still paying the price of the "first jihad", when mujahideen returning from Afghanistan caused serious problems for Yemen, including an armed conflict that had adverse effects on society and development.
Saeed al-Jamhi, who researches al-Qaeda and other Islamist groups and heads the Al-Jamhi Centre for Studies and Research, told Al-Shorfa he believes recruiting Yemenis and others to fight in Syria against the regime of President Bashar Assad in the name of religion is dangerous.
"Regardless of the positions taken by individuals and countries", he said, recruiting people to fight in the name of religion means "many enthusiastic youth will declare 'jihad' as they interpret it".
"This will make Syria a training ground for fighters and a source for al-Qaeda in the Arabian Peninsula, which poses an even greater threat than fighters trained in Afghanistan," he said.
JAN is the main beneficiary of such recruitment, which serves al-Qaeda's agenda – calling for revolt against Arab leaders in the name of religion, al-Jamhi said.
"After their return to Yemen, recruits will form a strong component for al-Qaeda in Yemen or other Arab countries since they will be considered ready fighters who spread extremism by force," he said.
JAN has become an extension of al-Qaeda in the Arabian Peninsula, he said, and some al-Qaeda members who fought alongside Ansar al-Sharia in Abyan have now joined JAN's forces.
"Al-Qaeda's strategy relies on entering lax areas where a conflict is raging so it can mix in and find a new foothold for itself", al-Jamhi said.
Tareq al-Fadhli, a former leader in al-Qaeda in Yemen, told Yemeni newspaper Aden Tomorrow on August 31st, 2012, that Ansar al-Sharia members "suddenly retreated from the cities of Zinjibar and Jaar in the Abyan province to join the war against the Syrian regime".
Al-Fadhli said he "does not exclude the hypothesis that the move was based on a regional agreement to transfer al-Qaeda fighters from Yemeni territory to Turkey then to the Syrian front."
“This explains the sudden withdrawal of these gunmen from Abyan,” he added.
Muslim cleric Zaid bin Abdul Rahman, head of Al-Nour Centre for Research and Studies, condemned calls by some clerics to "what they call jihad".
It is unacceptable to call for jihad, since the fighting in Syria does not meet the conditions of jihad, he told Al-Shorfa, adding that no matter what the conditions in Syria are, religion should not be used for fighting.
"We condemn the call to jihad, whether issued by Yemeni or Arab clerics or those from any other Muslim country," he said.