As engineers inched closer to connecting power at the tsunami-crippled Fukushima Daiichi nuclear plants, a strong 6.1 magnitude earthquake today rattled Japan's Ibaraki Prefecture. The prefecture is south of the stricken Fukushima No 1 nuclear plant. The country's meteorological agency however said no tsunami warning was issued.The quake shook buildings in Tokyo, but no damage was immediately reported. Public broadcaster NHK said, that flights at the capital's Narita Airport were temporarily suspended for safety checks.Tokyo Electric Power Co., which owns and runs the Fukushima Daiichi plant has stepped up efforts to bring electricity back to its crippled nuclear reactors to cool down the overheating spent fuel. Firefighters said they are increasing the spraying of water at the plant in a desperate attempt to avert a meltdown.Japanese Kyodo news agency said connecting a power line to the No. 2 reactor of the plant is expected to be completed during the day. Engineers have already connected a power cable to the outside of the plant. Further cabling is under way inside to try to restart water pumps in four of the six reactors. An official of the nuclear safety agency said they are scheduled to restore electricity at number 1 and 2 reactors today. He said reactors number 5 and 6 also will be powered today. They have also scheduled to restore power to number 3 and 4 tomorrow. At a press conference, Chief Cabinet Secretary Yukio Edano said the condition of the No. 3 reactor has become relatively stable following the water discharge. He said preparations are on to spray water into the No. 4 reactor to cool its spent fuel pool. The accident severity level at the plant was raised from four to five on the 7-point international scale yesterday.Meanwhile, Japan have detected elevated levels of radiation in milk and spinach in areas near the crippled nuclear power plant in Fukushima prefecture.