KATHMANDU (AFP) - A protest against next week's election in Nepal turned violent Tuesday as demonstrators torched vehicles and hurled explosives, the police said.

A 33-party alliance, headed by the Communist Party of Nepal-Maoist (CPN-M), is boycotting the Nov 19 vote, the country's second national election since a 10-year civil war ended in 2006.

The CPN-M, which says the election will be unconstitutional, had called for a nine-day halt to motorised transport beginning on Tuesday.

Protesters hurled a homemade bomb at a car Tuesday evening in Kathmandu, a police spokesman said.

Earlier in the day they threw bottles at a passenger van in the capital, injuring a child inside, he said.

"The protesters resorted to violence after thousands of drivers across the country defied the strike," the police spokesman said.

Police have arrested more than 100 demonstrators since Monday and say they plan a string of pre-emptive arrests in the coming days.

Protesters also set a motorcycle on fire and damaged a car in Syangja district in western Nepal.

The group has previously disrupted the distribution of election material and set several candidates' vehicles on fire.

More than 100 parties, including three major ones - the Unified Marxist-Leninist, the Nepali Congress and the Maoists - are fielding candidates for the 601-seat Parliament, which is also expected to act as a constitution-drafting body.