First signs of unrest since India restored mobile phone connectivity after a prolonged shutdown.
Separatists say ruling an "atrocity" and "attack on democracy" as police prepare for violence.
Authorities overnight detained 60 more people from the Jamaat-e-Islami, besides more than 100 held the previous night.
Rahim Nor says the talks are to unite the various liberation groups so that they will have one single voice when facing the Thai government.
He says Malaysia needs to find out what exactly the separatist groups want in terms of autonomy.
The march had been called by a platform set up in March to "defend Catalan institutions" and "the rights and fundamental freedoms" of its citizens.
Puigdemont, who lives in self-imposed exile in Belgium, had been visiting Finland since Thursday for talks with lawmakers.
Five people are held in custody, including Catalan presidential candidate Jordi Turull who was due Saturday to seek a second round vote in the regional parliament, after failing to be elected earlier in the week.
Some 45,000 people joined the "Republic Now" march called by the influential pro-independence citizens' group ANC.
China has voiced its opposition to both Taiwanese and Hong Kong independence.
Bangkok’s peace negotiation head says pilot project with separatist militants’ representative MARA Patani will hopefully pave way for lasting peace in southern provinces.
The separatists have been seeking to create an independent nation for over a year.
Catalonia's parliament will meet without Carles Puigdemont, who is in self-imposed exile in Belgium.
Spanish Prime Minister Mariano Rajoy also denied the idea of Carles Puigdemont leading Catalonia from exile, should he be elected president of Catalonia.
The influx of refugees is related to a separatist movement that has gained much traction in Cameroon.
Shouts of 'Puigdemont, president' fill the air after separatist parties won 70 seats out of 135.
Pattani-based Barisan Revolusi Nasional has been asked to register its demands with Malaysia, which is the facilitator for the southern Thailand peace process.