An opposition-led political general strike against next week's general elections has shut down schools, markets and industries across Nepal.

Hundreds of protesters attacked vehicles that defied the strike call and torched at least half a dozen buses and lorries.

Police arrested 51 protesters involved in the attacks.

The alliance of 33 opposition parties called the strike in an attempt to disrupt the November 19 elections.

It has called for a complete transport strike until polling day.

In the capital Kathmandu, police officers in riot gear guarded the main road junctions while armed soldiers patrolled the main highways.

Private businesses were closed and shops shut down, while non-striking government workers were forced to walk to their jobs.

Nepal's 12 million voters are set to elect members of the Constituent Assembly, which will write a new constitution.

The assembly was first elected in 2008 after protests forced King Gyanendra to give up direct rule.

Nepal was turned into a republic and the centuries-old monarchy was abolished.

But power struggles and differences among the political parties got in the way of writing constitution, and new elections were announced.

It was finally agreed earlier this year that a government led by the supreme court chief judge would supervise the elections.

The government has warned that anyone attempting to disrupt the vote would be jailed and property damaged by protests would be replaced.

Police said they had defused some improvised explosive devices.