Explosions rocked a packed railway station and crowded Hindu temple Tuesday in Hinduism's holiest city, and at least 12 people were killed and dozens injured, officials said. Hadass Balass, an Israeli tourist in Varanasi, told Channel 2 Tuesday evening that there was no news of wounded Israelis in the attack. Authorities were scrambling to determine what caused blasts, but political leaders suggested it was a bombing with the prime minister condemning the explosions and a top state official promising stern action against those responsible. Cities across India were put on high alert. Indian Prime Minister Manmohan Singh also appealed for calm, said his spokesman, Sanjaya Baru. The apparent attack on Hinduism's holiest site came days after Muslims and Hindus battled each other in the nearby city of Lucknow, and angry Hindus looted Muslim shops and burned vehicles in the coastal resort of Goa.