Pakistan's ruling coalition has strengthened its position by winning three National Assembly seats in by-elections held on Wednesday.

The victory [of the MMA] is a reflection of the anti-government and anti-American sentiment Talat Masood, analyst

Voters also gave three more seats to the six-party opposition Islamist alliance, the MMA, the Election Commission said.

The Pakistan People's Party (PPP) of former premier Benazir Bhutto has so far won none.

Official results in four more National Assembly constituencies, and 18 provincial assembly seats, are still awaited.

Prime Minister Zafarullah Khan Jamali's Pakistan Muslim League faction (PML-Q) has raised its total to 121 seats in the 342-seat legislature.

Mr Jamali leads a coalition with the Muttahida Qaumi Movement (MQM) and defectors from the opposition PPP.

Complaints

Unofficial results show the MQM won one National Assembly seat, while an independent candidate won another, but these have yet to be confirmed.

The seats became vacant after some MPs won in more than one constituency in general elections in October.

Mr Jamali's strength has been 'shored up'

If they win more than one seat, the additional seats fall vacant the moment they take the oath as an MP.

The PPP complained of vote rigging and violence mounted by the government's supporters.

It said three of its members had been shot dead and several others wounded in the south of the country. Officials say the deaths resulted from personal disputes.

Power boost

Some observers say the MMA's strong showing can be interpreted as the growing Islamisation of Pakistani politics.

The elections hurt the main opposition PPP

The MMA opposes the government's support for the US-led "war on terror" and is in power in North West Frontier Province, which borders Afghanistan.

"Their victory is a reflection of the anti-government and anti-American sentiment," says retired General Talat Masood, a political commentator.

But the BBC's Paul Anderson in Islamabad says the PML-Q's successes will shore up its position and attract support from independents and disaffected members of other parties.