The Central government on Wednesday claimed to have got some 'leads' on the Mumbai serial blasts that has as yet claimed the lives of about 190 suburban train passengers but remained tightlipped on who was responsible for it.

"We have leads about the Bombay blasts but no arrests have been made," Home Secretary V K Duggal told media persons after a meeting with Civil Aviation Minister Praful Patel and top officials in New Delhi on beefing up security at airports.

"Though there is no possibility of terrorist attacks on vital and prime economic installations following the Mumbai blasts, all systems are being put in place to ensure security," he said.

Duggal said the number of security equipments, manpower, baggage and personal check-in systems were being put in place. Appealing to passengers to cooperate with security officials at the airports, Patel said: "Some concrete decisions have been taken (in regard to the security beef-up) and these will be implemented."

Later in the day, Maharashtra Director General of Police P S Pasricha too claimed that certain leads had been found in the case.

Addressing a press conference in Mumbai, Pasricha said the state government's first priority in the wake of the blasts was to provide relief to the injured and much success had been achieved in this. "We have held meeting with authorities of both Western and Central Railways to discuss ways and means to restore normalcy as soon as possible," Pasricha said.

"Security has been tightened across Maharashtra. Metal detectors and dog squads will be deployed at railway stations," he said, adding that some measures will be implemented immediately while others will take some time to be put into effect.

He praised the citizens of Mumbai for displaying 'admirable resilience' and for lending a helping hand to their fellow citizens in the aftermath of the bombings. The police were interacting with political and religious leaders and asking them to counsel their followers to maintain calm and restraint, he said.