Pakistani Taliban Thursday claimed responsibility for a suicide attack in the country's eastern city of Lahore to avenge a military offensive in the northwest and vowed further deadly strikes, according to local press reports.

"We claim responsibility for the Lahore suicide attack. It is revenge for the Swat military operation," Hakimullah Mehsud said from an undisclosed place, saying that he was a spokesman for Pakistan Taliban chief Baitullah Mehsud.

Baitullah Mehsud commands Tehreek-e-Taliban (TTP), or the Pakistani Taliban, is Pakistan's most wanted militant with a five- million-dollar reward posted by the United States.

On Wednesday, about 30 people were killed and another 300 wounded when a van packed with explosives levelled a police building and damaged the provincial headquarters of the Inter- Services Intelligence (ISI) agency in Lahore, capital of Pakistan' s Punjab province.

Baitullah has also claimed responsibility for a gun, grenade and suicide assault on a police academy near Lahore on March 30.

"If the government, at the behest of America, launches more operations against us, more government installations will be targeted," said Hakimullah Mehsud, who is a commander and deputy to Baitullah Mehsud.

"I love the common citizens of Pakistan. I appeal to them to vacate their cities as there will be more such massive attacks, more dangerous than this and we will target government buildings and places," Mehsud added.

He claimed one mujahid, holy fighter, carried out Wednesday's attack, first firing on security officials and then blowing up a " red van".

Mehsud claimed that a united TTP had a "large number" of suicide bombers in Punjab, Pakistan's most populous province and the country's political heartland.

A group called "Tehrik-i-Taliban Punjab" also claimed responsibility in a statement posted on Turkish jihadi websites through an intermediary organization, said U.S. specialist group SITE.

But a senior Pakistani security official said that investigators believed no such splinter organization existed.

Meanwhile, Pakistan Thursday offered rewards for tips leading to the capture alive or dead of 21 Taliban leaders and commanders in the country's northwest.

The information department of the North West Frontier Province (NWFP) has issued to newspapers and TV channels names and pictures of 21 Taliban leaders with their positions.

A reward of five million rupees (about 62,500 U.S. dollars) for information about Maulana Fazlullah, chief of Taliban's Swat chapter, has been announced.

It is offering four million rupees (about 50,000 U.S. dollars) each for information about Taliban spokesman Muslim Khan and two deputy chiefs of the group, Shah Duran and Ibn-e-Amin.

Muslim Khan is a famous face among the Swat Taliban for his frequent interaction with the local and foreign media.

Shah Duran is known for his speeches on Taliban's FM radio and is considered to be the hardliner among the Taliban leaders.

It is the first time that the government has announced rewards for the information leading to the arrest of Taliban leaders.

The people have been asked to provide information to the government on three phone numbers and that the names of informers would be kept secret.

The advertisement says, "Are those Muslims and patriots who have deprived mothers, sisters and daughters of shelter in Malakand division? Think yourself. Such people are murderers of human being and deserved to be punished. Help the government to take them to justice."

The security forces launched operations against Taliban militants late April after they refused to vacate the Buner district neighboring the Swat district of the NWFP as promised and challenged the writ of the government.