Australian police says the MH17 crash site in Ukraine is still too dangerous for investigators to enter.
The comment comes after a team of Dutch and Australian police officers postponed a trip to the site amid intensifying unrest in eastern Ukraine.
Tony Negus is the Australian Federal Police Commissioner.
"In the area that we're interested in, absolutely, the fighting intensified overnight. Now, whether the intensification diminishes over coming days and creates a more permissive environment, it may be as early as today that we say that that fighting has diminished enough for us to go back in. But last night the fighting was intense."
Ukrainian troops increased their assaults on territory held by rebels on Sunday, in an attempt to gain control over the area where MH17 was downed.
The conflict is raging in at least five places.
13 people including two children have been killed in the fighting in the Donetsk region.
Russian Foreign Minister Sergei Lavrov and U.S. Secretary of State John Kerry have called for an immediate ceasefire in the region.
Lavrov says the two countries agree it is important to start talks between the Ukraine government and rebels.
But the U.S and Russia keep blaming each other for hindering the investigation, and accusing each other of contributing to the escalation of violence in eastern Ukraine.
The EU reached an agreement last week to impose further sanctions against Russia.
Russia, in response, is accusing the EU of curtailing bilateral cooperation.
Russia also says it has set up its own team of experts to investigate the plane crash.
So far, a total of 227 coffins containing the remains of the victims have been sent to the Netherlands for identification.
