16. Restricted cash

Restricted cash amounted to €7.9 million on 31 December 2015, and decreased to €7.7 million on 31 December 2016. This decrease is related to the payment of a claim to Charles River by decrease of the escrow account for €0.3 million, which has been slightly offset by an increase in non-current restricted cash of €0.1 million related to an increase in the bank guarantee with regard to the rental of additional office space for the Belgian premises.

Restricted cash on 31 December 2016 is related to €0.4 million and €0.7 million of bank guarantees on real estate lease obligations in Belgium and in the Netherlands respectively, and to €6.6 million escrow account containing part of the proceeds from the sale of the service division in 2014 for which the release will be possible after final agreement between the parties.