(Adds Turkey summoning French diplomat over Erdogan caricature)
* Charlie Hebdo publishes cartoon of Erdogan
* Turkey vows retaliation for "disgusting effort"
* Row has its roots in beheading of French teacher
* Anti-French protests widen to Mali, Somalia
By Tuvan Gumrukcu and Ece Toksabay
ANKARA, Oct 28 (Reuters) - Turkey's president said on Wednesday that Western countries mocking Islam wanted to "relaunch the Crusades", heightening a confrontation with France over cartoons of the Prophet Mohammad that have stirred anger in Muslim-majority countries.
In a speech to lawmakers of his AK Party in parliament, President Tayyip Erdogan said that standing against attacks on the Prophet was "an issue of honour for us", suggesting Ankara may be digging in for a prolonged standoff.
The row with France flared after a French teacher who showed pupils cartoons of the Prophet published in the French satirical weekly Charlie Hebdo was beheaded in France this month. The caricatures are considered blasphemous by Muslims.
In a sign of spreading anger at France's defence of the right to publish the cartoons, demonstrators denounced France in street protests in several Muslim-majority countries.
"France down, it insulted our Prophet," protesters shouted in the Somali capital Mogadishu.
Furthering Turkish anger, Charlie Hebdo published a cartoon on its cover showing Erdogan sitting in a white t-shirt and underpants, holding a canned drink and lifting the skirt of a woman wearing an Islamic hijab to reveal her naked bottom.
Turkish officials said Ankara would take legal and diplomatic steps in response to the caricature, calling it a "disgusting effort" to "spread its cultural racism and hatred".
The Turkish foreign ministry summoned the charge d'affaires at the French embassy over the magazine cover.
Erdogan said he had not seen the caricature "because I consider it wrong to even look at these immoral publications" and that his anger was over disrespect towards the Prophet rather than the "disgusting attack directed at me".
The West was "once again headed to a period of barbarity", he said, describing colonial powers as "murderers" for their record in Africa and the Middle East.
"They literally want to relaunch the Crusades. Since the Crusades, the seeds of evil and hatred have started falling on these (Muslim) lands and that's when peace was disrupted."
The French government, backed by many citizens, saw the Oct. 16 knife attack - in which a man of Chechen origin beheaded Samuel Paty, a teacher who had shown pupils cartoons of the Prophet in a civics lesson - as an attack on freedom of speech.
Macron has said he would redouble efforts to stop conservative Islamic beliefs subverting French values.
Turkish state media said Turkish prosecutors had launched an investigation into Charlie Hebdo's executives. Turkey's Communications Directorate said the battle against "these rude, ill-intentioned and insulting steps" would continue to the end.
PROTESTS WIDEN TO SOMALIA, MALI
Erdogan sharply criticised Macron at the weekend, saying the French leader needed a mental health check, prompting France to recall its ambassador from Ankara. On Monday, Erdogan urged a boycott of French products.
France's foreign ministry on Tuesday issued safety advice to French citizens in Indonesia, Turkey, Bangladesh, Iraq and Mauritania, advising them to exercise caution. They were told to stay away from any protests over the cartoons and avoid any public gatherings.
In Cairo, Egyptian President Abdel-Fattah al-Sisi said freedom of expression should stop if it offended more than 1.5 billion people.
The Grand Imam of Egypt's al-Azhar university, one of the world's most eminent seats of Sunni Muslim learning, urged the international community to criminalise "anti-Muslim" actions.
In the Somali capital Mogadishu, hundreds of mostly youthful demonstrators gathered at a busy junction leading to the airport, chanting anti-French slogans and burning French flags. They were responding to calls by clerics to come out and condemn France and boycott French products.
"We are going to use our muscles to defend Islam," a middle-aged man, Mohamed Ahmed, who was at the demonstration, told Reuters when asked why he was participating. "We ask people to burn every product of France they come across."
Dozens of Iranians gathered in protest in front of the French embassy in Tehran, state media reported. Some held up placards with red crosses plastered on images of French goods.
In Dhaka, hundreds of Bangladeshi Muslims took to the streets of the capital for a third consecutive day, chanting slogans such as "Boycott French products" and burning effigies of Macron, whom they described as an enemy of Islam.
At a much larger protest on Tuesday in Dhaka, thousands had turned out for a protest carrying banners such as "Stop Islamophobia", "Boycott France" and "Lay siege to the French Embassy in Dhaka". (Additional reporting by Abdi Sheikh in Mogadishu, Ruma Paul in Dhaka, Nadine Awadalla and Ulf Laessing in Cairo; Writing by William Maclean; Editing by Jon Boyle, Nick Tattersall and Nick Macfie)
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