By Idrees Bakhtiar BBC correspondent in Karachi

The Government of Pakistan has placed an advertisement in newspapers seeking help in arresting Osama Bin Laden and other al-Qaeda leaders.

Sunday's advertisement begins with verses of the Koran stressing respect for human life

The advertisement describes Bin Laden and 17 of his associates as terrorists and seeks the people's help with information leading to their capture.

The advertisement does not offer any reward, unlike a similar advertisement published on Saturday.

In this, Pakistani police published photographs of 10 alleged militants suspected of carrying out the recent deadly bombings in the southern city of Karachi.

That advertisement, accompanied by photographs of the 10 suspects, offered rewards of up to 20m rupees ($320,000) and was carried by several local papers.

Secrecy assured

Sunday's advertisement seeking information leading to the arrest of al-Qaeda leaders begins with verses of the Koran stressing respect for human life.

Some senior al-Qaeda members are already in custody

These are followed by photographs of Bin Laden, his senior lieutenant Amin al-Zwaheri, and 16 others.

This is the first advertisement issued by the Pakistani government seeking their arrest.

It has asked the people of Pakistan to help with information leading to the apprehension of these men, describing them for the first time as terrorists.

The advertisement assures potential informants that the special telephone lines opened for the purpose are being manned by army officers and that the identities of informants will be kept secret.

Continuing manhunt

Saturday's advertisement offered rewards for information leading to the arrest of people suspected of involvement in the murder of US journalist Daniel Pearl, and two massive bomb attacks.

Police are also hunting Pakistani militants

In the first of these, a number of French naval engineers who were helping the Pakistani navy build a submarine, were killed when their bus was blown up.

The second attack, close to the US Consulate-General in Karachi, did not hurt any foreigners, but killed and injured a number of Pakistanis.

The advertisements appear shortly after 10 Pakistani soldiers were killed in a gun battle with suspected al-Qaeda fighters in Pakistan's north-western frontiers close to Afghanistan.

A large number of Pakistani troops with reported help from US personnel are combing the mountainous tribal territories in search of al-Qaeda fighters and their leaders.