Three serial blasts rocked crowded areas in Zaveri Bazar, Dadar and the Opera House in Mumbai last evening killing 21 people and injuring 141. Confirming the death toll the Maharashtra Chief Minister said that the blasts were a terror strike. Mumbai Police spokesperson Nisar Tamboli said teams of Maharashtra Anti Terrorism Squad (ATS), Mumbai Police and the fire brigade immediately rushed to the sites of explosion. The police said that seven improvised explosive devices were used for the blasts. Investigators do not rule out possibilities of use of RDX. Security has been beefed up across Mumbai. Two forensic teams from Hyderabad and New Delhi reached Mumbai and inspected the blast sites. A 6-member National Investigation AgencyTeam has arrived in the city to assist Maharashtra police in the investigations into the serial blasts. This team is in addition of 7 -Member team already in the country's commercial capital. Massive relief and rescue operations are on. The Home Minister Mr.P.Chidambaram, who rushed to the city around midnight visited the blast sites and reviewed the security situation. He said in Delhi before leaving that explosions were a coordinated attack by terrorists. Mr. Chidambaram said that all the injured have been admitted in hospitals and their number could rise. Maharashtra Chief Minister, Prithviraj Chavan has said the blasts were indeed a terrorist attack and were caused by highly explosive devices, IEDs. He described the blasts as an attack on India's sovereignty and on Mumbai's spirit. He said they were aimed at creating communal disharmony and was proud of the people of Mumbai who maintained calm. The Chief Minister also said that all hospitals in Mumbai have been put on alert. He said Maharashtra government will bear expenses of medical treatment of those injured in the blasts. The hospital helpline numbers are- KEM Hospital- 022-24136051 Nair Hospital -022- 23085379 Saifee hospital-022-67570111 Mr. Chavan said that information is being gathered about the agency involved in the attack and it would be premature to name any organisation behind the attack. No terror outfit has claimed responsibility for the attack. High security alert has been sounded all over the country. Last evening the Prime Minister Dr. Manmohan Singh spoke to Maharashtra Chief Minister and asked him to do whatever is possible to provide relief to the injured and to the families of the deceased. The Prime Minister also directed the Union Home Minister P.Chidambaram to provide all possible assistance to the State Government. He appealed people of Mumbai to remain calm and show a united face. President, Vice President, Prime Minister, Lok Sabha Speaker and the UPA Chairperson and several other leaders have condemned the bomb blasts and expressed deep condolence over the loss of lives. America and Britain have condemned the terror act in Mumbai. Bangladesh and Pakistan have also condemned the blasts.