The backlash against President Emmanuel Macron's comments on Islam intensified Sunday, with Turkish President Recep Tayyip Erdogan again urging him to have "mental checks" and many Muslims demanding boycotts of France.

Speaking after teacher Samuel Paty was beheaded for showing caricatures of the Prophet Mohammed to pupils in a lesson on free speech, Macron vowed France would "not give up cartoons" and said Paty "was killed because Islamists want our future".

But Erdogan on Saturday urged Macron to have "mental checks" for treating "millions of members from different faith groups this way" -- comments which prompted Paris to recall its envoy to Ankara.

The Turkish leader doubled down on those comments Sunday, accusing Macron of being "obsessed with Erdogan day and night".

"(Macron) is a case and therefore he really needs to have (mental) checks," he said in a televised speech in the eastern Anatolian city of Malatya.

Relations between Macron and Erdogan have become increasingly strained over geopolitical issues ranging from a Greek-Turkish maritime dispute to the conflict between Armenia and Azerbaijan.

The European Union's top diplomat, Josep Borrell, called the comments Erdogan made on Saturday "unacceptable" and urged Turkey "to cease this dangerous spiral of confrontation."

'Attacking Islam'

Anger at Macron spilt over into the streets in several Muslim-majority countries, with further demonstrations expected Sunday.

In Deir Al-Balah in the Gaza Strip, Palestinians burnt portraits of Macron, calling his comment "an attack and an insult against Islam."

"We condemn the comments of the French President... and whoever offends the Prophet Mohammed, whether through words, actions, gestures or drawings," said Maher al-Huli, a leader of Hamas, the Islamist movement that runs the coastal Palestinian enclave.

Pakistani Prime Minister Imran Khan accused Macron of "attacking Islam".

He tweeted that the French leader "could have put healing touch & denied space to extremists rather than creating further polarisation & marginalisation that inevitably leads to radicalisation."

In Libya, social media users called for demonstrations on Sunday afternoon -- calls echoed by a religious TV channel linked to Mufti Sadek al-Ghariani, the war-torn North African country's controversial top religious leader.

"If a Muslim leader made the same racist and hostile statements about the West as Macron did about Islam, he would be accused of being extremist, racist and terrorist," said Ghariani.

Several Libyan towns and cities had already seen rallies by demonstrators brandishing placards bearing slogans such as "the Prophet is a red line" and pictures of Macron with his face crossed out in red.

"As Muslims, it's our duty to respect all the prophets, so we expect the same from all other religions," said housewife Fatima Mahmoud, 56, who said she would attend a demonstration in Tripoli. "Demonising Islam and Muslims isn't going to keep the social peace in France."