Thousands of opposition activists squatted on railroad tracks and highways across Bangladesh on Wednesday, halting trains and other traffic to demand reforms ahead of next year's elections, witnesses and news reports said.

No violence was immediately reported. The opposition has vowed to paralyze transportation across the country.

A 14-party opposition alliance led by former Prime Minister Sheikh Hasina has been demanding removal of four election commissioners, saying they are biased toward Prime Minister Khaleda Zia's four-party ruling coalition.

The commissioners have denied the allegation and refused to resign.

At Tongi, a major railroad junction just outside Dhaka, more than 3,000 demonstrators gathered on the tracks, holding up several trains.

Riot police guarded the junction, but there were no immediate clashes with the protesters.

Another 2,000 activists squatted in a railroad station in northeastern Sylhet city, disrupting train communications, TV station ATN Bangla reported.

Activists also squatted on highways, blocking vehicles and leaving many commuters stranded, the TV station reported.

Similar disruptions were reported in several other districts, it said, without providing details.

Traffic was thin in Dhaka, the capital city of 10 million people. Commuters relied on tricycle rickshaws and a few state-run buses because most other vehicles were off the streets.

Authorities deployed 12,000 security officers, including members of a paramilitary force, in Dhaka, a city police official said on condition of anonymity in line with policy.

The opposition alliance has launched a campaign of street protests and general strikes to press for its demands, a common opposition tactic in Bangladesh.

The alliance also wants to play a role in choosing the head of a caretaker administration that will conduct the elections after Zia constitutionally hands over power Oct. 28.

The post usually goes to the immediate past chief justice, but the opposition has said that would mean handing power to a man who was once a member of Zia's Bangladesh Nationalist Party.

The opposition also wants other new arrangements for the election, including a voter list with photographs and transparent ballot boxes.

On Tuesday, Zia accused the opposition of creating anarchy and attempting "to disrupt peace and democracy," the United News of Bangladesh agency reported.