Pakistan's interior minister Rehman Malik has said the government would not allow banned outfits and parties to take out any rallies or advertise themselves.
His warning came during a meeting held in Karachi to review the law and order situation in the Sindh province.
The warning also came a day after Hafiz Mohammad Saeed, the leader of the Jamaat-ud-Dawah rubbed shoulders with leaders of some mainstream religious parties in Lahore during a rally taken out to condemn Israeli atrocities and express solidarity with Palestinians.
Hameed Gul, a former chief of the ISI was also present in the rally that has placed the Pakistani government in yet another embarrassing position due to the presence of Saeed who is accused by the Indian government for masterminding the 2008 Mumbai attacks.
Rehman said that the government was firm it would not allow banned outfits to hold rallies and would take necessary action to deal with them.
"Their activities will be banned, even if they are operating under the garb of new names", Malik told the media after the meeting at the chief minister's house.
Saeed wanted by the Indian government was released from house detention last month on court orders and also took part in a farmers rally recently.
His party has also held rallies in Multan and some other cities in recent times with the Punjab government facing criticism over the presence of some of its minister's at rallies of the JuD and other banned religious outfits.
The meeting was called to control the spate of target killings in the city which are being put down to ethnic and religious differences among some parties.
More then a dozen activists of ethnic and religious parties have been gunned down in target killings leading to riots in some areas of Karachi since last Saturday.
The minister said that President Asif Ali Zardari has said that he wants peace in the city at all cost.
"The President said that everybody wants peace in Karachi which is the economic hub of Pakistan", Malik said adding there was a consensus in the meeting that peace should be maintained at every cost in Karachi.
"We have decided to take severe action against the culprits and whosoever, is involved in target killings will be arrested and taken to task. There is 'zero tolerance' for criminals and anti-social elements," he said.
He said that SHO of different areas has been directed to compile data of all prominent religious figures in his area and hold meetings with them to maintain religious harmony.