Violent clashes rocked several Zambian towns in the wake of the country's fourth multi-party elections, amid allegations of vote rigging by supporters of presidential hopeful Michael Sata.

As results filtered through after the 28 September poll, presidential incumbent Levy Mwanawasa, of the Movement for Multiparty Democracy (MMD), appeared to be heading for his second and final five-year term of office.

The erosion of Sata's opposition Patriotic Front's (PF) early lead saw protestors taking to the streets on Sunday, clashing with security forces in the capital Lusaka and towns in northern Zambia. There have been no reports of fatalities.

After the first two days of counting, Sata had scooped all Copperbelt and Lusaka urban parliamentary seats by large margins and commanded more presidential votes than any other candidate in Northern and Luapula provinces, establishing a vote tally of 50 percent, ahead of Mwanawasa's 28 percent and the United Democratic Alliance's (UDA) presidential candidate Hakainde Hichilema's 20 percent.

Sata, who held cabinet positions in both the governments of founding president Kenneth Kaunda and Mwanawasa's predecessor Frederick Chiluba, declared himself the winner with a projected overall vote tally of 55 percent overall.

But after results from 120 of the 150 constituencies were announced late on Sunday, Mwanawasa took a commanding lead with 42 percent while businessman Hichilema was second on 28 percent and Sata's support tumbled to 27 percent.

News of Sata's third place ranking led to hundreds of PF supporters pouring onto the streets in at least five Lusaka townships, blocking major roads while carrying placards saying "We say no to Mwanawasa's dictatorship" and "We are ready to die for Sata". Police responded with teargas, amid reports of looting and incidents of arson.

Zambia's police inspector general, Ephraim Mateyo, hinted the protests could have been a case of "sour grapes by some disgruntled politicians".

"We have made a number of arrests in various parts of the country and we are investigating who could be inciting these people to riot. The law will take its course once we establish the man behind these protests which are disturbing our peace," Mateyo told IRIN.

A Lusaka-based political analyst who declined to be identified said the demonstrations were probably provoked by disappointment and not necessarily incited by any individual. "These cases of protesting residents are only coming from areas that have out-rightly rejected Mwanawasa going by the election results.

"The only problem is that such people are failing to reason that while they don't appreciate Mwanawasa's policies, others perhaps have seen them working and have therefore, given him another five-year mandate," the analyst said.