Military intervention in Syria would be a mistake, UN-Arab League envoy to Syria Kofi Annan cautioned, as a senior Syrian official switched to the opposition. \"We have to be careful that we don\'t introduce a medicine that is worse than the disease,\" Annan told reporters Thursday at the Arab League\'s headquarters in Cairo ahead of his trip to Damascus Saturday. \"We don\'t have to go very far in the region to find an example of what I am talking about,\" the former U.N. secretary-general appointed last week as the special representative said after meeting with league Secretary-General Nabil al-Araby. Annan said he intended to press the Assad regime \"for the cessation of hostilities and an end to the killing and violence -- but of course the ultimate solution lies in a political settlement.\" He called for \"appropriate\" political reforms. The United Nations and Arab League have appealed to Syrian President Bashar Assad to step aside in an orchestrated power transfer. Annan\'s caution against armed foreign intervention was echoed by Turkish President Abdullah Gul, who warned separately that foreign intervention could be perceived as \"exploitation\" of the sectarian-charged conflict. US Sen. John McCain, R-Ariz., called this week for U.S.-led airstrikes against Syrian military installations. \"We do not think it is right for the powers outside the region to intervene in the region. We think it is more appropriate for the region to solve this issue by itself,\" Gul told reporters in Tunis, Tunisia, as he stood beside interim Tunisian President Moncef Marzouki, who offered asylum to Assad. Also Thursday, a top Syrian oil ministry official announced he defected from the Assad regime and challenged other ruling-party members to follow suit. \"I declare that I am joining the revolution of this nation, which did not and will not accept injustice, despite the brutality of this regime and its supporters, to crush the people who are seeking their freedom and dignity,\" Deputy Oil Minister Abdu Hussameldin, said in a video posted on YouTube and circulated by Syrian activists. \"I don\'t want to end my career in the service of this regime\'s crimes,\" he said. \"I declare that I am joining the revolution of the dignified people.\" Hussameldin said Assad had \"pushed the country to the edge of the abyss.\" The 58-year-old father of four said he expected the regime would \"burn my home\" and \"persecute my family\" in retribution for his defection. A Syrian oil ministry spokeswoman confirmed to The Wall Street Journal the man in the video was Hussamedin, one of two assistants to the refining minister. Hussameldin is the highest-level official defecting in the year-old conflict, which the United Nations says has left more than 7,500 people dead. Syrian troops stormed towns around the western-central city of Hama, a key uprising area, and appeared Thursday ready to move into northern towns, activists said. At least 56 people were killed across the country, including 47 in Homs, whose Baba Amr neighborhood was held by rebels for several months before regime forces drove them out March 1 after nearly four weeks of relentless shelling. All but three of those killed in Homs were executed, the Local Coordination Committees activist network said. The report couldn\'t be verified. Valerie Amos, UN undersecretary-general for humanitarian affairs and emergency relief, said Thursday she was \"devastated\" by the annihilation in Baba Amr and by the fact that almost no one was there. \"That part of Homs is completely destroyed and I am concerned to learn what happened to the people in that part of the city,\" she said.