Security forces rounded up all top leaders of major political parties except Nepali Congress President Girija Prasad Koirala and Nepal Communist Party-UML general secretary Madhav Kumar Nepal early Thursday.

Nepali Congress general secretary Ramchandra Poudyal, Nepali Congress (Democratic) acting President Gopalman Shrestha, Nepal Communist Party UML Politburo member Ishwor Pokharel, CPN-UML spokesman Pradip Nepal, Sujata Koirala (daughter of G P Koirala), were among the 200 arrested during overnight raids.

Security is tight around residence of top political leaders and their telephones are also being tapped, party sources said.

The government is overreacting and is spreading terror in the country the name of security, CPN-UML general secretary Madhav Kumar Nepal said. "The government is scared of the peaceful demonstrations being launched by the seven party alliance," he told PTI over phone.

"We will defy the government's ban and organise our protest shows as usual on Friday," he said, adding that there will be nationwide protest shows against the government, people will throng the streets and thousands will court arrest.

Meanwhile, authorities severed Internet services, both landline and mobile telephone services on Thursday but later restored landlines and internet communications.