Kosovo Prime Minister Isa Mustafa on Friday condemned the bombing attack on the country's parliament, describing it as "terrorizing."
"The Assembly is the highest legislative body, a symbol of our state and democratic order. No one will be allowed to terrorize institutions of our state," Mustafa said on his Facebook page.
Police said the attack was "executed at 11 pm (2100 GMT) with an explosive device from a distance," without specifying its type.
Local media quoted police sources as saying that attackers fired a rocket-propelled grenade and fled on a motorcycle, which was later found burning in another part of the capital Pristina.
The incident took place as long-standing tensions flared up again between Mustafa's coalition and the nationalist opposition over a border agreement with Montenegro.
The cabinet had sent the deal to parliament for ratification earlier Thursday.
Over the past year, the opposition has repeatedly fired tear gas in parliament and held street protests in attempts to block the border agreement along with a deal on expanded rights for minority Serb communities.
The largest opposition party, Vetevendosje, on Thursday held a protest, without any incidents, against the border demarcation agreement.
A smaller opposition party, the Alliance for the Future of Kosovo (AAK), condemned the attack as "criminal act ... against Kosovo and its citizens."
Kosovo is a former Serbian province with a mostly Albanian population. It gained independence in 2008, nine years after a war on its soil drew NATO to intervene against Serbia.
The young country remains volatile and plagued with problems - from high-level corruption to ethnic tensions to rampant unemployment - despite billions of dollars that the European Union and the international community have poured into missions assisting it.