Lucknow, Jan 6 (IANS): At least 20 flights bound for New Delhi were diverted to Chaudhary Charan Singh airport here late Sunday due to dense fog in the national capital, airport officials said Monday.

The Lucknow airport tarmac has the capacity to accommodate 24 planes at a time, and with the sudden landing of 20 flights diverted from Delhi, the airport was chock-a-block with planes.

The private carriers had to bring in their ground staff to deal with the sudden rush of aircraft and flurry of passengers.

Airport officials told IANS that more than 5,000 passengers were stranded here.

With fog in Delhi as well as Lucknow showing no signs of thinning away, passengers' wait might get prolonged.

"There is almost zero visibility at the Indira Gandhi International Airport in Delhi and the situation is no different here, the flights will have to wait till the weather clears," an official said.

The diverted planes began landing at the Lucknow airport after 9 p.m. Sunday, officials said.

Daily flights between Lucknow and Delhi were also affected and officials said these services will remain crippled until the fog clears.