The authorities of Heathrow Airport said Wednesday morning that the strike of British Border Agency workers had not disrupted the immigration checks at the airport so far. \"Due to the effective contingency plans we have put in place with the airlines and the UK Border Agency over recent days, immigration queues are currently at normal levels,\" said a statement released by the London airport, one of the busiest airports in Europe. However, it warned there is still a possibility of delays for arriving passengers later in the day. More than two million British public sector workers held a 24-hour strike between midnight Tuesday and midnight Wednesday over the goverment\'s pension reform plan. The airport indicated earlier that immigration queues at the airport for non-EU passengers could be two to three hours. It has asked airlines to halve the number of passengers they fly into the airport to try to minimize any disruption caused by the strike. The airport also deployed hundreds of additional customer services staff within the terminals who are equipped with iPads and Blackberries to keep passengers up to date and are giving 24-hour support to passengers, providing information, food and drink. According to the government\'s pension reform plan, the public sector staff will have to work longer before retiring and pay more for pensions and switch from final-salary to career average schemes.