Two suicide bombers in Pakistan have killed at least 20 people and wounded many more in separate blasts on military targets in Rawalpindi, outside the capital, Islamabad. In Islamabad, VOA's Barry Newhouse has details.

The first bomb struck a bus on the main road between Rawalpindi and Islamabad Saturday.

Police said the bomber rammed a car filled with explosives into a bus carrying employees of Pakistan's Inter-Services Intelligence Agency.

Army spokesman Wahid Arshad said the other attack occurred near a checkpoint outside army headquarters.

"The suicide bomber blew himself up closer to the picket when he was stopped. He was killed and two people were injured," he said. "As far as the bus is concerned, 13 people have lost their lives, who were sitting on the bus and the suicide bomber also was dead."

The death toll from the attacks rose after police discovered more bodies in the wreckage.

A similar attack occurred in September, when a suicide attacker targeted a bus carrying intelligence agency personnel and a bomb detonated in Rawalpindi, together killing about 25 people.

Officials have suspected the attacks are linked to military operations against pro-Taliban militants in the Swat and Shangla districts of the Northwest Frontier Province.

Meanwhile, representatives of former Prime Minister Nawaz Sharif say he plans to return to Pakistan on Sunday afternoon. Pakistani officials have not said if they will try to deport him, as they did when he attempted a similar return from exile in September.

The former prime minister was exiled in Saudi Arabia after General Pervez Musharraf deposed him in a military coup in 1999.

Mr. Sharif's Pakistan Muslim League Party is part of a coalition of opposition parties considering boycotting January's parliamentary elections.

The coalition wants President Musharraf to end emergency rule and reinstate ousted Supreme Court judges in the next four days or they will not participate in the elections.

Former cricket star and opposition leader Imran Khan told reporters Saturday that participating in the polls would only give General Musharraf's presidency more legitimacy.

"If we take part in this election, we will be helping, resurrecting a military dictator," he said.

Former Prime Minister Benazir Bhutto's Pakistan People's Party has not indicated if it would join a boycott. Candidates wishing to run in the election must register by Monday.